Mr Mohamed has said he was tortured while he was held in US custody
A UK resident detained at Guantanamo Bay has released alleged MI5 memos which he claims show government collusion in his interrogation.
Ethiopian-born Binyam Mohamed, 30, told the Mail on Sunday they were sent to the CIA in November 2002, at a time he said he was being tortured in Morocco.
His claims of British collusion are being investigated by the government.
He also told the paper he was held in continual darkness for weeks on end in a prison in Kabul, Afghanistan.
Mr Mohamed claims MI5 agents fed his US captors specific questions which led to him falsely confessing to terrorist activities.
In the first memo, the writer asked for a name to be put to him and then for him to be questioned further about that person.
The second telegram asked about a timescale for further interrogation.
Mr Mohamed claims he acquired the telegrams through the US legal process when he was fighting to be freed from Guantanamo Bay.
Daniel Sandford, BBC Home Affairs correspondent, said Mr Mohamed's claims would be relatively simple to substantiate.
"As time progresses it will probably become quite apparent whether indeed these are true telegrams and I think it's unlikely they'd be put into the public domain if they couldn't eventually be checked back."
The Conservatives have called for a police inquiry into his allegations of British collusion.
Shadow Justice Secretary Dominic Grieve said there should be a judicial inquiry into the allegations and the matter referred to the police.
Mr Mohamed told the paper the worst part of this captivity was in Kabul's "dark prison".
"The toilet in the cell was a bucket," he told the paper.
"There were loudspeakers in the cell, pumping out what felt like about 160 watts, a deafening volume, non-stop, 24 hours a day.
He added: "They chained me for eight days on end, in a position that meant I couldn't stand straight nor sit.
"I couldn't sleep. I had no idea whether it was day or night."
Shami Chakrabati, director of campaign group Liberty said: "These are more than allegations - these are pieces of a puzzle that are being put together.
"It makes an immediate criminal investigation absolutely inescapable."
The legal organisation Reprive, which represents Mr Mohamed, said its client was shown the telegrams in Guantanamo Bay by his military lawyer Lieutenant Col Yvonne Bradley.
Mr Mohamed spent just under seven years in custody, four of those in Guantanamo - the US's camp in Cuba.
He was arrested in Pakistan in 2002 as US authorities considered him a would-be bomber who fought alongside the Taleban in Afghanistan.
But last year the US dropped all charges against him, and he was released in February.
A Foreign Office spokesman said: "We abhor torture and never order it or condone it.
"We take allegations of mistreatment seriously and investigate them when they are made.
"In the case of Binyam Mohamed, an allegation of possible criminal wrong-doing has been referred to the Attorney General.
"We need now to wait for her report."