LONDON, March 8 (UPI) -- A former Guantanamo Bay, Cuba, terrorism detainee says memos from the spy agency MI-5 prove Britain colluded with CIA captors who were torturing him.

British resident Binyam Mohamed, who returned home last month after his release from nearly seven years of imprisonment at the U.S. prison camp in Cuba and other locales, cited MI-5 memos purporting to show how British officials orchestrated his questioning while interrogators in a Morocco prison sliced his genitalia with a scalpel, The Sunday Times of London reported.

Mohamed, speaking Saturday to reporters for the first time since he was arrested in 2002, said he underwent "nightmarish tortures" that drove him "close to insanity." He told reporters that one interrogator in Morocco took his penis in his hand and cut it up to 30 times.

Britain's attorney general, Patricia Scotland, has been under pressure to launch a criminal investigation of MI-5 over torture allegations, and Mohamed's claims is likely to add to that pressure, The Sunday Times reported.