The Ministry of Defence must release some information on people held or captured by British forces in Afghanistan, according to an administrative appeals tribunal ruling.
The dates of detention, and details of transfers to Guantanamo Bay or elsewhere, must be given, it ruled.
Information from special forces will still be withheld for “security reasons”, however.
An All-Party Parliamentary Group on Extraordinary Rendition had to request the information using the Freedom of Information Act.
The MPs have yet to establish how many people were kidnapped. The British government knew about torture and the security services were complicit in its use.
The court also ruled that Britain’s policy on capture and renditions should not be released for security reasons.