The US has published four secret memos detailing legal justification for the Bush-era CIA interrogation programme.

Critics of the programme say the methods used amounted to torture.

President Obama has also issued a statement guaranteeing that no CIA employees will be prosecuted for their role in the interrogation programme.

Some in the CIA wanted parts of the memos to be blacked out, fearing full disclosure could trigger lawsuits against agents, reports suggest.

The release of the memos stems from a request by civil rights group the American Civil Liberties Union (ACLU).

I never imagined I would say this, but Stella Rimington is right. The former head of MI5 who made her career running the security service's dirtiest operations in the 1980s, against the miners' union and the IRA, has warned that the government has given terrorists the chance to find "greater justification" by making people feel they "live in fear and under a police state". Naturally, ministers described her remarks as nonsense and accused her of playing "into the hands of our enemies".

Khaled al-Maqtari told Amnesty International he was held in isolation for more than 28 months without charge or access to any legal representation.

He said he first became a US "ghost detainee" at Abu Ghraib prison in Iraq after being arrested there in 2004.

The US has not acknowledged detaining Mr Maqtari.

US President George W Bush did acknowledge the existence of black sites in 2006.

He said the prisons were a vital tool in the US "war on terror" and insisted that the CIA had treated detainees humanely and had not used torture.

In July 2007, Mr Bush issued an executive order which banned "cruel, inhuman or degrading treatment" of terrorist suspects by the CIA, but not its operation of secret facilities. The agency has since declined to say whether it still uses them.

A former SAS soldier was served with a high court order yesterday preventing him from making fresh disclosures about how hundreds of Iraqis and Afghans captured by British and American special forces were rendered to prisons where they faced torture.

Ben Griffin could be jailed if he makes further disclosures about how people seized by special forces were allegedly mistreated and ended up in secret prisons in breach of the Geneva conventions and international law. Griffin, 29, left the British army in 2005 after three months in Baghdad, saying he disagreed with the "illegal" tactics of US troops.

He told a press conference hosted by the Stop the War Coalition this week that individuals detained by SAS troops in a joint UK-US special forces taskforce had ended up in interrogation centres in Iraq and Afghanistan, as well as Guantánamo Bay. He had not witnessed torture himself but added: "I have no doubt in my mind that non-combatants I personally detained were handed over to the Americans and subsequently tortured."

Referring to the government's admission that two US rendition flights containing terror suspects had landed at the British territory of Diego Garcia, Griffin said the use of British territory and airspace "pales into insignificance in light of the fact that it has been British soldiers detaining the victims of extraordinary rendition in the first place".

The Ministry of Defence said it did not comment on special forces' activities.

In a separate move, the media have been prevented by a court order from reporting a court martial of six SAS soldiers charged with a conspiracy to "defraud of a value of about £3,000".