10 Under the subheading "General considerations" the respondent says:
It is fundamental to the effective operation of an organisation such as ASIO that the specific details of its areas of interest, the identity of subjects of security interest, the degree of its ability to obtain intelligence in relation to those subjects, its sources, investigative techniques and work methods (modus operandi), its successes and the information derived from its successes, be kept in the strictest possible secrecy. This secrecy can extend to neither confirming nor denying if certain activities have occurred, as to do so could compromise current or future activities or operations, expose ASIO's collection and analysis methods or place officers or other persons at risk.
11 The respondent goes on to say that, for the reasons he proceeds to give, the documents over which public interest is claimed on a class basis in this proceeding are paradigm examples of documents that ASIO should not be required to disclose save in the most exceptional circumstances.
12 Under the heading "Security assessments" the respondent describes the process involved in making more complex security assessments, which were less than 3% of assessments made in the financial year ending 30 June 2008. The process involves deploying a range of investigative powers and methodologies in order to acquire information from a wide range of sources. That information is then used by ASIO to assess whether a particular person poses a direct or indirect threat to Australia's national security. The respondent continues:
When the above process is complete in most, but not all cases, ASIO presents the results of that process in a "Final Appreciation" document (although the document may or may not be headed in that way). Where a complex case warrants the generation of a Final Appreciation, it ordinarily takes the form of an ASIO minute, in which ASIO records not just its assessments as to whether or not an adverse security assessment should be issued in relation to a particular individual, but in which it also sets out the investigative process, the security issues that have been identified and required resolution, and the methods used to gather evidence or corroborate information.
13 If the investigative branch assesses that an individual is a threat to Australia's national security, the respondent is advised, usually through a Director‑General's Briefing Note (DGBN), and often both a DGBN and a Final Appreciation are provided to the respondent for decision on whether an adverse security assessment should be issued pursuant to Part IV of the Australian Security Intelligence Organisation Act 1979 (Cth) (the ASIO Act).
14 The respondent expresses the opinion that it is imperative that Final Appreciations be as comprehensive as possible in the information they contain, including the reasoning and evidence the investigative branch considers supports an adverse assessment. This is because the administrative consequences flowing from an adverse assessment can be severe, and because the consequences of failing to issue such an assessment where one is warranted can also be severe. The respondent continues:
Accordingly, it is vital that I be given complete and accurate information upon which to base my decision whether an adverse security assessment should be issued. If any information were to be withheld from the Final Appreciation as a result of a concern that, if it was included, that information might thereafter be disclosed, that would impair ASIO's capacity to give accurate advice to government and my capacity to make appropriate decisions in relation to whether adverse security assessments should be issued.
15 Under the heading "the class of documents over which public interest immunity is claimed", the respondent explains that an adverse security assessment is a written document, often a facsimile, by which ASIO advises the relevant department, in each of these cases the former Department of Immigration, Multicultural and Indigenous Affairs, that ASIO assesses the individual to be directly or indirectly a risk to Australian national security. He says that the assessment itself contains little information that, if disclosed, would prejudice national security. The assessments have been provided to the applicants subject to very minor redactions.
16 The respondent says it is the documents on which a security assessment is based, namely the Final Appreciation (however that document is headed) and any associated DGBN, that cannot be disclosed without damaging the public interest. He continues:
Accordingly, the class claim advanced in this case concerns the class of documents shortly described as "Final Appreciation documents and related briefing notes". Documents in this class invariably contain specific detail as to the reasons why persons are assessed as a risk to Australia's national security (if they are so assessed), and specific detail of the intelligence sources and methods used by ASIO in obtaining relevant information and conducting its assessment functions. They are documents that are often highly classified and that disclose ASIO's sources, methods and capabilities to a high level of detail. Further, they do so in a manner that readily permits ASIO's methodology and interests to be identified. They are, therefore, one of the classes of documents held by ASIO that require the greatest level of protection.
The public interest in the non‑disclosure of documents in the class identified above is particularly acute when access to documents in that class is sought by a person against whom an adverse security assessment has been issued. That follows because in such a case access to very sensitive information is sought by one of the very small number of people whom ASIO assesses to be most likely to use such information in a way that would damage Australia's national security.
17 The parts of the respondent's affidavit which have been summarised or set out above consist of pars 1 to 32. None of the text has been redacted. There are minor redactions of one word at the head and foot of each page, not forming part of the text. The last paragraph (par 33) preceding significant redactions to the next five pages of the text (pars 34‑62 except for five lines of an unnumbered paragraph) states that there are four specific features of the information commonly found in Final Appreciations that support the proposition that, as a class, ASIO should not be required to disclose those documents save in the most exceptional circumstances. It is apparent from the text that resumes after the redactions end that the ensuing material has dealt with three of the specific features referred to in par 33.
18 Paragraph 62 deals with the fourth feature - "Prejudice to on‑going investigations". The respondent states that the revelation of the extent of ASIO's knowledge in relation to a person who is of security interest is potentially extremely damaging to Australia's national security. Armed with that knowledge, such a person will be able to ascertain where there are gaps in ASIO's knowledge or coverage of the person's activities, and then to exploit those gaps in a way that may remain unknown to ASIO. The disclosure of a Final Appreciation to the subject of an adverse security assessment may, for example, reveal:
· gaps in ASIO's knowledge of the subject's activities;
· ASIO's understanding of current methods and modus operandi of groups and individuals, which could then be altered or disguised to avoid detection or monitoring by intelligence agencies and/or to cause harm;
· ASIO's own methodologies, which could then be exploited in the various ways described in the affidavit; or
· the length of time that ASIO has been reviewing particular topics or types of intelligence, which in turn may reveal the identity of a person or group of interest to ASIO or in relation to which ASIO may have intelligence holdings.
19 The respondent says that subjects of security assessments will often be interviewed by ASIO. This will be noted in the Final Appreciation, and will often provide an insight into the kind of information that ASIO sought to elicit during the interview, ASIO's assessment of the answers that were given and the techniques it used in seeking that information. The respondent concludes the "prejudice to on‑going investigations" topic by observing that the disclosure of the Final Appreciation document would therefore frequently reveal important information concerning ASIO's methodology, in addition to the specific information about ASIO's state of knowledge.
20 Two paragraphs of the affidavit dealing with "prejudice to on‑going investigations" have been redacted (pars 64 and 68).
21 The respondent concludes the Class Claim part of his affidavit by saying:
All of the above considerations support the conclusion that Final Appreciation documents, and summaries thereof, are documents the disclosure of which is very likely to damage Australia's national security. They are documents that, as a class, should be required to be disclosed only in the most exceptional circumstances, and not in these cases.
22 The affidavit in its redacted form has been made available to the applicants' solicitors. The unredacted parts of the affidavit contain additional information.