workable rule which can be applied by SIAC (or similar bodies which may have to deal with the same problem). 154. Several possible ways of approaching the issue were mooted in the course of argument. Counsel for the appellants advanced the proposition that once the issue has been raised that a statement may have been obtained by the use of torture the onus should rest upon the Secretary of State to prove beyond reasonable doubt that it was not so obtained. I would unhesitatingly reject this proposition as unsustainable. That is confirmed by experience of inordinately long voir dires in terrorist cases in which the admissibility of confessions has been contested. Not only would the process severely disrupt the course of work in SIAC, it would be wholly impossible for the Secretary of State to obtain the evidence of the parade of witnesses commonly called in such voir dires – gaolers, doctors, interviewers etc – to cover in minute detail the time spent in custody by the maker of the statement. The opposite extreme suggested on behalf of the Secretary of State was that the appellant should have to prove on the balance of probabilities that a challenged statement was obtained by the use of torture before it is rejected. The objections in principle and practice to the imposition of such a burden on an appellant are equally conclusive. He may not even know what material has been adduced before SIAC. The special advocate is given the material, but he has little or no means of investigation and is not permitted to disclose the information to the appellant or his solicitors, so has no one from whom to obtain sufficient instructions. 155. I agree with your Lordships that consideration of this question by the conventional approach to the burden of proof is both unhelpful and inappropriate. It seems to me rather to equate to the process described by Lord Bingham in R v Lichniak [2002] UKHL 47, [2003] 1 AC 903 at para 16 as “an administrative process requiring [the board] to consider all the available material and form a judgment”; cf Re McClean [2004] NICA 14, para 77, where McCollum LJ said of a similar process that it was “not the establishment of a concrete fact but rather the formulation of an opinion or impression”, which was not capable of proof in the manner usually contemplated by the law of evidence. I accordingly agree with the view expressed by Lord Bingham (para 56 of his opinion) and Lord Hope (para 116) that once the appellant has raised in a general way a plausible reason why evidence adduced may have been procured by torture, the onus passes to SIAC to consider the suspicion, investigate it if necessary and so far as practicable and determine by reference to the appropriate test whether the evidence should be admitted and taken into account. -83-