2 DUGGAN J. The appellant was convicted by verdict of a jury in the District Court on a charge of possessing methylamphetamine for the purpose of sale. He has appealed against conviction on grounds which allege that the information was bad for duplicity and that the verdict of the jury was uncertain. He also claims that the trial judge misdirected the jury on the onus of proof.

3 According to the prosecution case, on 1 August 2000 police officers observed the appellant alight from the driver's side of a vehicle which was parked in a driveway alongside a block of flats situated on Tapleys Hill Road, Seaton. The police officers spoke to the appellant about the ownership of the vehicle and then searched it. They found a small black bag on the front passenger seat. There were two small plastic bags (P5) in the black bag, each of which contained a white substance which was later identified as methylamphetamine. The combined weight of the methylamphetamine in the bags was 1.34 grams.

4 In addition, the police officers found a set of electronic scales and a number of mobile telephones in the vehicle. There was a text message recorded on one of the mobile telephones which was consistent with an incoming request for the supply of a drug.

5 The appellant was then conveyed to the Port Adelaide Police Station where he was questioned and searched. During the search the police officers found a plastic bag (P8) hidden in the appellant's underpants. On later analysis it was found to contain 6.65 grams of methylamphetamine. The appellant was not questioned about the plastic bag and its contents because he had indicated towards the end of the interview which had just taken place that he did not wish to comment further.

6 The appellant was presented for trial in the District Court on an information which read as follows:

"Fiorini Zampogna on the 1st day of August, 2000 at Seaton, knowingly had methylamphetamine, a drug of dependence, in his possession for the purpose of selling it to another person."

7 When the appellant was arraigned his plea was recorded in the transcript as:

8 This plea was not accepted by the prosecution and the trial proceeded. The appellant gave evidence. He said he was the owner of P5, the two packets of amphetamines found in the vehicle. He stated that he had borrowed the vehicle, but discovered it would not start after he had visited a friend who lived in the block of flats. He said he called the RAA and was waiting for an RAA patrol when the police arrived. He said it was a cold night and he took a coat from the car and put it on. It belonged to an acquaintance by the name of Tracy Fabian.

9 The appellant said that while the police officers were at the vehicle, he put his hand into the pocket of the coat and felt the plastic bag P8. He had not known before that it was in the pocket. He realised that it could contain drugs because Tracy Fabian was a user of amphetamines. The appellant said that at this stage he panicked and, when the attention of the police officers was diverted, he took the bag out of the pocket of the coat and put it in his underpants. This occurred while he was still at the vehicle. He said he did this in order to hide the package and that he had no further intention in mind. He agreed that P8 was found by the police officers in the course of the subsequent search at the police station.

10 Tracy Fabian was called by the defence to corroborate the appellant's version. She said she knew the appellant and she confirmed that she was a user of amphetamines. She said she was in the habit of buying large amounts of amphetamines in one lot because it was more economical. She then shared the drugs with friends. She said that on 1 August 2000 the appellant gave her a lift to premises she wanted to visit. She said that she had purchased a quantity of drugs the night before and placed them in the pocket of her coat. When she got out of the vehicle after being dropped off by the appellant she inadvertently left her coat, with the drugs in the pocket, in the vehicle.

11 The jury returned a verdict of guilty. It was suggested at the hearing of the appeal that there was some ambiguity in the verdict in that, when considered in conjunction with the summing-up, there is doubt as to whether it related to the charge of possession for sale or the alternative verdict which was available, namely, guilty of simple possession of the amphetamine. I will comment on this issue subsequently, but I will proceed on the assumption that the jury found the appellant guilty of possession of the drug for the purpose of sale.

12 The appellant's concession, made as part of his plea, that he was guilty of possession, resulted in confusion in the subsequent conduct of the case. The prosecutor conducted his case throughout on the assumption that there would be no dispute as to possession by the appellant of both P5 and P8. Presumably, this assumption was based on the wording of the appellant's plea. Despite the different explanations given in evidence by the appellant for his possession of P5 and P8 respectively, the prosecutor's final address to the jury proceeded on the basis that there was no dispute that the appellant was found in possession of both P5 and P8. He reminded the jury of the appellant's plea and the statement included in it that the appellant was guilty of possession. The prosecutor related the admission to all the drugs which had been found. He put to the jury that the only issue in contest was whether the appellant had satisfied the jury on the balance of probabilities that the methylamphetamine was not for the purpose of sale. In this respect he was referring to the operation of s 32(3) of the Controlled Substances Act, 1984 which provides as follows:

"For the purposes of this section, a person who knowingly has in his or her possession more than a prescribed amount of a drug of dependence or a prohibited substance, being an amount that is prescribed for the purposes of this subsection, will, in the absence of proof to the contrary, be presumed to have that drug or substance in his or her possession for the purpose of the sale or supply of that drug or substance to another person."

13 In his final address to the jury, defence counsel stated that it was open to the jury to find that the appellant was not in possession of P8 because it had been in the coat pocket without the appellant's knowledge. Referring to the appellant's plea he added:

"He pleaded guilty at the outset to possession of amphetamine. It is a question for you whether that plea goes to the amphetamine in P5 or both lots of amphetamine; the small bags and a larger bag that he found in the pocket and tried to hide from the police unsuccessfully. That's a question for you. His Honour will direct you on that."

14 The trial judge commented to the jury in his summing-up that the appellant had "admitted possession of methylamphetamine, albeit that his plea did not necessarily extend to all of the methylamphetamine found". Later in his summing-up he said:

"In this case there is an issue as to possession and it arises this way: the accused admits that he had possession of the two packets of methylamphetamine found in the car, and I am talking about Exhibit P5 here, and has, indeed, pleaded guilty to simple possession, but he had not by that plea necessarily admitted possession of the methylamphetamine later found in the search of his underpants."

15 As previously stated, the plea to the lesser offence was not accepted by the prosecution. There is authority to the effect that, in these circumstances, the plea itself is deemed to have been withdrawn, but the fact of the plea can be used as evidence of an admission of matters which are inherent in it; R v Hazeltine [1967] 2 QB 857 at 862; R v Notman [1994] Crim L R 518; R v Lee [1985] Crim L R 798. As the commentary to R v Lee states (799):

"The 'plea' is not conclusive but it is evidence against the defendant, like any other admission, and its relevance will depend on the course that the trial takes."

16 The comments made by the defence counsel in his address to the jury which are set out above acknowledge that the plea was equivocal in that it was open to the interpretation either that the appellant admitted he was in possession of P5 alone or that he was in possession of both P5 and P8. Presumably, defence counsel was aware of his client's version of the incident at the time the plea was entered. It is unsatisfactory that, at this stage of the case, he said nothing about the ambiguity which he should have realised was inherent in the plea. Instead, as I have already observed, the ambiguity as to what the appellant meant by his plea led to confusion as the trial unfolded.

17 I have pointed out that the prosecutor's final address proceeded on the basis that the appellant had acknowledged possession of both P5 and P8. He did not differentiate between the two exhibits when speaking of the effect of s 32(3). He said that the presumption provided for in s 32(3) arose because the appellant was in possession of both P5 and P8. Defence counsel asked the jury to find that the appellant was in possession of P5 but not P8. However, as stated above, he said in his address that it was for the jury to decide whether the appellant had admitted by his plea that he was in possession of both lots of amphetamines. The ambiguity resulting from the plea was not resolved at any time during the case.

18 I think it is possible that the appellant intended his plea of guilty to possession of the drug to extend only to P5. However, that was not the way in which the prosecutor put the matter to the jury in his final address.

19 If the jury accepted the prosecutor's assertion that the appellant's plea amounted to an admission that he was in possession of P8 as well as P5, they may well have accepted his further invitation to find that the presumption applied as a consequence and that the appellant was required to prove on the balance of probabilities that the drugs were not in his possession for the purpose of sale. In my view the ambiguity in the plea rendered it inappropriate to use it as part of this line of reasoning.

20 The directions to the jury gave rise to a further difficulty which could well have affected the jury's understanding of the circumstances which would give rise to the operation of s 32(3).

21 The trial judge told the jury that a finding that the appellant had P8 in his possession could be based on the version which the appellant gave in evidence. His Honour said:

"The matter doesn't end there, however, because you must then consider what he did with the drugs. On his own evidence, if you accept it, he tricked the police by distracting them and then switching the package from his coat pocket into his underpants. If you think he did that, you will then ask yourselves whether, by that time, he knowingly had physical control over the package and was intending to exercise physical control over it. You might think that, in doing what he says he did, he was exercising a power to dispose of it, or attempt to hide it, but that's a matter for you. That's a factual determination for you.

In considering this question, you are also entitled to have regard to what happened later. On the police evidence, which was not contradicted, he attempted to keep the package concealed by not fully removing his underpants when he was strip-searched. Do you think he was then exercising physical custody and control of the package? Well, that's a matter for you.

As to this element generally, you should, on the accused's own admissions, find that he was in possession of at least one of the two packages, the one weighing 1.34 grams. As to the remaining package found in his underpants, it is a matter for you to determine, based on the direction I've just given."

22 The trial judge returned to this topic later in his summing-up when commenting on arguments raised by defence counsel in the course of his address. The trial judge said:

"He suggested to you that if your find that Mr Zampogna found the packet in his pocket, panicked and hid it, and didn't intend to keep it, then you should be satisfied that he was not in possession of it.

I have already directed you as to the law relating to possession, and you will need to consider that submission in the context of my direction. Do you think that by first hiding it in his underpants and then later attempting to conceal it during the body search, the accused was exercising control over it, or attempting to? That's a matter for you."

23 The argument that possession of P8 could be established on the appellant's version of what he did to trick the police had not been relied upon by the prosecutor. If the jury found that the appellant was in possession of P8 by this process of reasoning, it was open on the directions they were given to find that the presumption in s 32(3) arose by reason of possession established on this basis. However, no mention was made of the difficulty associated with applying the presumption in these circumstances. The prosecution argued strongly against an acceptance of this aspect of the appellant's evidence. If the jury found that the appellant was in possession of P8 on his own version of the facts, it would seem that they would also have to accept that possession in those circumstances was not for the purpose of sale, but to hide his friend's drugs from the police.

24 As a result of this consideration and the concerns which exist with respect to the ambiguity in the plea, there was a clear risk of the jury proceeding by way of impermissible reasoning to the conclusion that the condition precedent for the operation of the presumption had been established.

25 I will return to these issues after dealing with the argument put on behalf of the appellant that the information was bad for duplicity.

26 Prima facie, a count in an information must not allege more than one offence: Johnson v Miller [1937] HCA 77; (1957) 59 CLR 467 at 487; Hamzy (1994) A Crim R 341 at 343; Criminal Law Consolidation Act 1935 Schedule 3 r 4(1). The rationale of this rule was explained by Gaudron and McHugh JJ in S v The Queen [1989] HCA 66; (1989) 168 CLR 266 at 284:

"The rule against duplicitous counts in an indictment originated as early as the seventeenth century ... It may be ... that the rule grew out of the strict formalities associated with criminal pleadings at a time when the difference between misdemeanour and felony was the difference between life and death. However, the rule against duplicitous counts has, for a very long time, rested on other considerations. One important consideration is the orderly administration of criminal justice. There are a number of aspects to this consideration: a court must know what charge it is entertaining in order to ensure that evidence is properly admitted, and in order to instruct the jury properly as to the law to be applied; in the event of conviction, a court must know the offence for which the defendant is to be punished; and the record must show of what offence a person has been acquitted or convicted in order for that person to avail himself or herself, if the need should arise, of a plea of autrefois acquit or autrefois convict ...

The rule against duplicitous counts has also long rested upon a basic consideration of fairness, namely, that an accused should know what case he or she has to meet."

27 In addition to true or actual duplicity, an indictment can also suffer from latent duplicity by reason of ambiguity which arises in the course of the prosecution case: Johnson v Miller at 486. This will occur when the evidence led by the prosecution discloses that more than one alleged offence is relied upon to support one count in the information or complaint. In some cases the ambiguity can be removed by amendment or by requiring the prosecution to elect to place reliance on one alleged offence to the exclusion of others.

28 This is not to say that the prosecution is prevented from attempting to prove certain offences by establishing a number of individual acts which can be properly identified as part of the same criminal enterprise or the one criminal activity: Walsh v Tattersall [1996] HCA 26; (1996) 188 CLR 77 at 107; Hamzy at 348. By way of example, a single count of supplying a drug can be based on different acts of supply which are capable of being classified as part of the one criminal activity: Deng (1996) 91 A Crim R 80 at 87. Again it might be permissible to charge in a single count an offence of possession of drugs when there are separate parcels of drugs, but no relevant separation in the time or circumstances of possession: Eades (1991) 51 A Crim R 151.

29 It would be unhelpful to lay down hard and fast rules of guidance for the courts or prosecutors in cases involving possession of drugs in circumstances similar to the present case. Multiplicity of charges is not to be encouraged as the solution for all cases. On the other hand, there will be some cases in which fairness or the potential for uncertainty in the verdict will render it appropriate to present the accused on separate charges.

30 In the present case, I do not think there was actual or latent duplicity in the information on which the appellant was presented. It was alleged that he was in possession of two parcels of amphetamines, one found on his person and the other on the front passenger seat of the vehicle which he had been driving. P8 was not located until the appellant was searched at the police station. However, it was not in dispute that it had been on the person of the appellant when he was apprehended in the vicinity of the vehicle. P8 consisted of a large quantity of the drug and P5 was comprised of two smaller packets in quantities suitable for street sales. Paraphernalia commonly used for drug trafficking was found in the vehicle. These composite circumstances were relied upon as constituting one offence of being in possession for the purpose of sale. In my view, it was not inappropriate in these circumstances to charge only one count of possession for sale.

31 Furthermore, I am of the view that latent ambiguity in the charge did not become apparent in the course of the prosecution case. It was alleged that the appellant was in possession of both P5 and P8 and that, together, they constituted the methylamphetamine which was the subject of the charge. This was the prosecution case as it was explained in the opening and final addresses of the prosecutor.

32 However, the matter does not end there. Duplicity aside, it remains necessary to enquire whether the conduct of the case generally led to uncertainty in relation to the verdict which was of such a nature as to result in a miscarriage of justice. In this respect, regard must be had to the directions given to the jury which the appellant asserts gave rise to uncertainty in the verdict.

33 After explaining the concept of possession in unexceptionable terms, the trial judge reminded the jury that, on the version given by the appellant in evidence, he was in possession of P5. However, he instructed the jury that the presumption as to the purpose of possession provided for in s 32(3) could not arise upon proof that the appellant possessed P5 alone. This was because the weight of the drugs in P5 was less than the prescribed amount. His Honour then went on to explain that the presumption could only arise if it was proved that the appellant was in possession of both P5 and P8.

34 The trial judge then dealt with the different bases on which the appellant could be found guilty of possession for sale. He explained that the appellant could be found guilty of possession for sale on the basis of possessing P5 alone. He said that, in that event, the statutory presumption would not arise, but it would be open to the jury to infer from the surrounding circumstances that the packages in P5 were in the appellant's possession for the purpose of sale. His Honour commented that the prosecutor had left this alternative to the jury. In fact that was not correct. As I have said, the prosecution case at all times was that the appellant was in possession of both P5 and P8 and it was alleged that the presumption arose from the possession of both parcels. The prosecutor did point to various factors apart from the presumption which he said supported the inference that the drugs were in the appellant's possession for the purpose of sale, but he did not refer to those matters in the context of a submission that the jury should convict the appellant of possession for sale if he was found to be in possession of P5 alone.

35 The trial judge then explained to the jury that, as an alternative, the appellant could be found guilty of possession for sale if it was proved that he was in possession of both P5 and P8 and he failed to rebut the presumption which would then arise under s 32(3). Finally, the judge referred to the further alternative discussed earlier in these reasons of the appellant being in possession of P8 on the version given by him in evidence that he was hiding the drugs from the police out of panic.

36 It follows from these directions that the jury could have found the appellant guilty of possession of the drug for sale, either on the basis of possession of both P8 and P5 or by way of possession of P5 alone. Furthermore, possession of P8 could have been established on the basis suggested by the prosecutor that the appellant was aware of the existence of P8 all along or, as the jury were also directed, on the appellant's version that he tried to hide P8 from the police when he realised that it was in the pocket of Tracy Fabian's coat.

37 I have already commented on the difficulty in using the appellant's own version as a basis for finding that he was in possession of P8. As to the other alternatives, it is not possible to say whether the verdict was based on possession of both P8 and P5 or P5 alone. This has important implications when it comes to fixing penalty. It is true that trial judges are often required to determine an appropriate factual basis for sentencing when a verdict could have resulted from one of a number of avenues to conviction. However, that task would be difficult in the present circumstances.

38 In a case such as the present there may be a number of paths to conviction which are technically open on the evidence. However, it is important from a practical viewpoint to have regard to the way in which the case has been conducted and, in particular, the basis upon which the prosecution case has proceeded.

39 In this case, the prosecution was prepared to assume responsibility for proving that the appellant was in possession of both P5 and P8. If the case had been left to the jury on this basis, the complexity and uncertainty which arose subsequently would not have eventuated. The alternatives left to the jury created complexity with respect to the application of s 32(3) as well as rendering the verdict uncertain.

40 In my view the combined effect of the ambiguous plea, the manner in which the plea affected the conduct of the prosecution and defence cases and the directions on possession arising from the appellant's version in evidence led to uncertainty in the verdict which, in turn, resulted in a miscarriage of justice.

41 There are two further matters. During the hearing of the appeal leave was granted to add a ground of appeal which complained of the directions of the trial judge in relation to the effect of s 32(3).

42 In the passages complained of, the trial judge referred to a "change in the onus of proof" with respect to that element of the charge which requires possession to be for the purpose of sale. According to the argument, this may have conveyed to the jury that the prosecution was not required to establish this element of the offence.

43 I do not think there was any danger of the jury being misled by the terminology used by the trial judge. He explained that the prosecution must prove that the appellant had the drug in his possession for the purpose of sale. He went on to refer to the presumption which would arise if the prosecution established beyond reasonable doubt that the appellant was in possession of more than the prescribed amount. He explained that the presumption could be rebutted by the appellant if it were established on the balance of probabilities that the possession was not for the purpose of sale.

44 That having been said, it would be better, in my view, if the effect of the section was not explained in terms of a change of onus, although I appreciate that this is sometimes said in the course of jury charges. There is a sense in which that statement is true, but there is a risk of confusing the operation of the onus in relation to the presumption with the overall onus in relation to proof of this particular element of the offence. The onus of establishing the element of purpose for sale remains throughout on the prosecution, albeit that proof is aided by the presumption.

45 Finally, there was a suggestion made in the course of argument on the appeal that the verdict may have been ambiguous for another reason. This was not made the subject of a ground of appeal. The transcript records that a verdict of guilty was returned. There is no record of what was said during the taking of the verdict and the summing-up did not deal with the manner in which the verdict would be taken, although the trial judge did explain to the jury the circumstances in which it would be appropriate for them to return a verdict of guilty of the alternative offence of simple possession of the drug. The point raised on appeal was whether the verdict of guilty might have related to possession of the drug and not possession of the drug for sale.

46 In my view it is unnecessary for the trial judge to instruct the jury in the summing-up on the precise manner in which the verdict will be taken. On the other hand, it is essential that the verdict be taken in such a manner as to leave no room for ambiguity. This can be addressed at the time the verdict is taken. It is appropriate at this stage to advise the jury that an alternative verdict will only be taken if it becomes necessary to do so after the taking of the verdict on the charge as stated in the information.

47 I would not be prepared to find on the material before this court that the verdict was taken in such a way as to leave room for ambiguity.

48 For the reasons which I have stated I would allow the appeal, set aside the conviction and sentence and direct a re-trial on the information.

49 GRAY J. I agree that this appeal should be allowed. I agree with the orders proposed by Justice Duggan and with his reasons.