It is necessary then to consider whether the agreement under which the gold, the gems and the safe were entrusted to the company's custody contravened the National Security (Exchange Control) Regulations in any respect and, if so, what was the effect of such a contravention on the plaintiff's right to maintain the action. By reg. 14 (1) of those regulations, which were in force at the relevant time, every person who had any gold in his possession or control was required to deliver it to the Commonwealth Bank within one month after it came into his possession or control. And, by reg. 14 (3), all gold so delivered thereupon vested in the Bank free from any mortgage, charge, lien, trust or other interest, the Bank being directed to pay for the gold to the person delivering it, on behalf of all persons having any interest therein, at the price fixed by the regulations. Until delivery to the Bank, therefore, the gold remained the property of the plaintiff although, on the date when it was deposited with the company, the time had long passed when it should have been delivered to the Bank. The terms of the bailment required the company to hold the gold, along with the gems and the safe, in safe custody until such time as the plaintiff required them to be redelivered to him and, while apart from the provisions of the regulations he could no doubt have demanded their return at any time, the purpose common to both parties was that the company should hold them for an indefinite period and not part with them except to the plaintiff. So far as the gold was concerned, the performance of that agreement would, and in fact it did, contravene the regulations but it does not follow that the bailment of the gems and of the safe was tainted by illegality. If the terms of the bailment relating to the gold were severable from those relating to the gems and the safe the bailment of the latter chattels would be lawful. The test of severability was stated by Jordan C.J. in McFarlane v. Daniell [1] "If the elimination of the invalid promises changes the extent only but not the kind of contract, the valid promises are severable: Putsman v. Taylor [2] " [3] . Applying that test, it is clear that the plaintiff's rights of action in respect of the gems and the safe would not be answered by a defence of illegality based upon a breach of the National Security (Exchange Control) Regulations since the contractual obligation upon the company as to the return of the plaintiff's property on demand applied to every part of the property deposited whether demanded together with the rest of it or separately. In the case of the gold, however, the plaintiff could not succeed if he was obliged to rely upon the illegal transaction to establish his case. The learned trial judge considered that proof of the bailment was not an essential part of the plaintiff's case. He based his conclusion upon the well known passage in Bowmakers Ltd. v. Barnet Instruments Ltd. [4] , that "a man's right to possess his own chattels will as a general rule be enforced against one who, without any claim of right, is detaining them, or has converted them to his own use, even though it may appear either from the pleadings, or in the course of the trial, that the chattels in question came into the defendant's possession by reason of an illegal contract between himself and the plaintiff, provided that the plaintiff does not seek, and is not forced, either to found his claim on the illegal contract or to plead its illegality in order to support his claim" [5] . With all respect, we are unable to agree with his Honour's view. In Bowmakers Ltd. v. Barnet Instruments Ltd. [4] , the plaintiff claimed damages for conversion. The conversion by the defendant was admitted as was the fact that the goods converted were the plaintiff's property. It is true that that property had come into the defendant's possession under certain hiring agreements which were said to have been unlawfully made, but the case was not one in which the plaintiff was obliged to rely upon those agreements to prove his case. They were irrelevant. The facts in the present case are very different. As the learned trial judge found, the gold and the gems had disappeared from the company's custody not later than April 1953. The tort of conversion was then complete, the Statute of Limitations began to run and, when the present proceedings were commenced, that right of action had been barred by the lapse of time. The general rule is that "where there has once been a complete cause of action arising out of contract or tort, the statute begins to run, and subsequent circumstances which would but for the prior wrongful act or default have constituted a cause of action are disregarded." (Wilkinson v. Verity [1] ; Betts v. Receiver for the Metropolitan Police District [2] .) Apart therefore from the contract of bailment, the failure by the company to redeliver the gold, the gems and the safe following the plaintiff's demand for them in 1959 would not have given rise to a new cause of action so as to defeat the statute. But the cases cited above show that the general rule is subject to an exception which is correctly stated in Halsbury's Laws of England, 2nd ed. vol. 33 par. 78, in these terms: "Where a bailee for safe custody has converted the goods, the bailor may demand their return and sue in detinue upon the bailee's breach of duty to deliver, although his remedy in trover is barred by statute". This is the course which the plaintiff followed in the present case and it was a course which he was obliged to follow to avoid being met by a defence of the Statute of Limitations. It meant, however, that he was obliged to prove the contract of bailment and, to support his claim in detinue, to rely upon the failure of the company to comply with the obligation imposed by it to redeliver the goods upon the demand which he made in 1959. It follows from what has been said that the plaintiff's claim to recover the value of the gold cannot be supported (A.R.P.L. Palaniappa Chettiar v. P.L.A.R. Arunaalam Chettiar [3] ) and to this extent the appeal must succeed.