Britain has reached a "full and final" settlement with former Libyan dissident Abdul Hakim Belhaj over his rendition to the regime of dictator Muammar Gaddafi.
Attorney General Jeremy Wright told the House of Commons that Prime Minister Theresa May has written to Mr Belhaj and his wife Fatima Boudchar to apologise for the "appalling" treatment they received.
Ms Boudchar is to receive £500,000 in compensation, said Mr Wright. But Mr Belhaj, 52, always made clear that he was not seeking monetary compensation and will not receive any.
The couple have fought a long legal battle over their claim that they were kidnapped and returned to Libya in 2004 in a joint M16-CIA operation linked to Tony Blair's infamous "deal in the desert" with Gaddafi.
They said that after three years evading Gaddafi's agents after fleeing Libya, they were seized in Malaysia and sent to Thailand for rendition to the north Africa country as a result of a tip-off from UK intelligence.
Ms Boudchar, who was five months pregnant at the time, was released shortly before giving birth, but her husband was held in prison and tortured for six years. He said that during his incarceration, he was questioned by British agents.
The settlement includes the withdrawal of claims against the British government, former foreign secretary Jack Straw, and former MI6 head of counter-terrorism Sir Mark Allen, said Mr Wright. But he stressed that there was no admission of liability from any of the defendants.
In her letter, Mrs May said that the UK Government believes their account of the events and told them: "Neither of you should have been treated in this way."
The Prime Minister wrote: "The UK Government's actions contributed to your detention, rendition and suffering. The UK Government shared information about you with its international partners.
"We should have done more to reduce the risk that you would be mistreated. We accept this was a failing on our part.
"Later, during your detention in Libya, we sought information about and from you. We wrongly missed opportunities to alleviate your plight: this should not have happened.
"On behalf of Her Majesty's Government, I apologise unreservedly. We are profoundly sorry for the ordeal that you both suffered and our role in it."
In a statement released by his lawyers, Mr Belhaj welcomed and accepted Mrs May's apology and said he extended his "thanks and sincere goodwill" to the Prime Minister and Mr Wright.
"For more than six years I have made clear that I had a single goal in bringing this case: justice," he said. "Now, at last, justice has been done.
"Today is a historic day, not just for myself and my wife. We hope our case will serve as a marker for future generations.
"A great society does not torture; does not help others to torture; and, when it makes mistakes, it accepts them and apologises. Britain has made a wrong right today, and set an example for other nations to follow."