On the specific point of a leak inquiry, he said it was a "long-established practice" of the Treasury not to comment on whether a leak inquiry has been established or not.
More than 100 institutions run by religious orders have been examined and the inquiry is expected to produce specific findings against a number of facilities.
The navy said it refused to comment on specific aspects of the case and has previously said a Service Inquiry established in September would assess current missing persons procedures.
For the 1992 debacle was the result of specific errors, identified subsequently in the Market Research Society's exhaustive inquiry into the matter and now absorbed by the pollsters.
The signatories encourage the Inquiry to look at the extent of provision of generic and theatre-specific cultural property awareness training for UK armed forces.