Iqbal Madni says he was arrested on a trip to visit relatives
A legal charity has begun a legal fight to force the UK government to reveal what it knew about an alleged CIA "rendition flight" in 2002.
Reprieve is to bring a case on behalf of a man who says he was tortured in Egypt after being flown there via the British territory of Diego Garcia.
Iqbal Madni, who was freed from Guantanamo Bay last year, claims he was tortured during a CIA interrogation.
The Foreign Office said the UK condemned torture "unreservedly".
Last year, Foreign Secretary David Miliband admitted Diego Garcia had been used for rendition flights, but the UK government has so far refused to reveal what else it knew about the flights.
Reprieve is taking legal action to obtain the release of UK government information relating to the flight involving Mr Madni, who spent six years in Guatanamo Bay detention camp.
Mr Madni, who was arrested on 11 January 2002 in Jakarta, Indonesia, believes his journey to Cairo took in a refuelling stop at a US facility in Diego Garcia.
He claims he was shackled tightly and packed in a wooden box on the flight, and told BBC File on 4 that he was later tortured in Egypt.
"When I arrived in Egypt I was blindfolded and left in a room... they interrogated me three times. Each was for 17 hours and they electrocuted me in my knees," he said.
"And they asked if I knew Osama Bin Laden or went to Afghanistan or if I met Richard Reid or knew anything about a shoe bomb or future attacks."
He claimed an American interrogator wrote down questions for others to ask.
Mr Madni said he had electric shocks passed through him repeatedly and he was made to drink drugged tea.
Clive Stafford Smith: "The issue is about what the British government knew"
Reprieve's Clive Stafford-Smith told the BBC that by analysing various statements from the British government about rendition flights it had deduced Mr Madni was on the flight which stopped at Diego Garcia.
"I would defy the British government to deny that we are right," he said.
"The issue for Britain is that Diego Garcia is a British territory, we're responsible for it and what happens on it... the Americans are meant to tell us what they are doing and we, as supervisor of Diego Garcia, have a responsibility to make sure that crimes do not happen on it."
He added: "I think particularly under the Blair administration there was an awful lot of playing the ostrich where the government knew what was going on but just buried its head in the sand.
"Now that's just wrong."
Mr Stafford-Smith added that when the government has been challenged over its knowledge of rendition flights "each time it has come forward and put its hands up and said, 'Ah, well, two people did fly through Diego Garcia,' they have refused to say who the victims are."
He also said: "To me that is utterly scandalous that you can commit an offence against an individual and then refuse the identity of that individual and refuse to let us at Reprieve help the poor guy get reunited with his legal rights.
FIND OUT MORE
Listen to File on 4, BBC Radio 4 2000 BST, Tuesday 28 July 2009, repeated 1700, Sunday 2 August 2009.
"I think that is so wrong and our government cannot stand there and say they are doing everything they can against torture when they continue to refuse to admit who the victims are."
A Foreign and Commonwealth Office (FCO) statement said: "The movement of detainees through UK territory without our permission, whilst concerning, does not mean that the UK has been complicit in torture. We condemn unreservedly any use of torture.
"The government never uses torture for any purpose, nor would we instigate or encourage others to do so."
The FCO added it was limited to what it could say about specific cases.
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