Dr. David Craig, director of the Republic's national archive, said the files were transferred in 1996 for safe keeping but, following further inquiries, the files were located on Tuesday morning.

BBC: Missing arms files turn up

The hearing will have access to an archive of 8, 000 secret files that were sent back to Britain after Kenya gained its independence in 1963.

BBC: Suspected Mau Mau activists in a prison camp, Nairobi, 1953

Their diaries and notes, together with complementary files on the 2002 Golden Jubilee, now form part of a vast archive held at Sussex University.

ECONOMIST: What three royal jubilees reveal about Britain

All the case files stored in huge safes at the site are to be transferred to the forensics archive in Birmingham.

BBC: Wetherby to Waco - DNA lab's demise