Abdel Hakim Belhadj, 45, is acting on allegations that Straw signed off papers approving his rendition.
Law firm Leigh Day & Co is representing Belhadj. Sapna Malik, a partner at the firm, said: “The civil action is against Mr Straw personally and seeks his response to allegations that he was complicit in torture and misfeasance in public office.”
Belhadj was the leader of the Libyan Islamic Fighting Group (LIFG), an organisation working in opposition to the Gaddafi regime. He claims that in 2004, CIA agents took him against his will from Thailand to Libya, via UK-controlled island Diego Garcia in the central Indian Ocean.
The former rebel insists he was tortured during the rendition process, as well as after his arrival in Libya.
It was revealed earlier this month that the British government had approved the rendition, and the Sunday Times ran an article at the weekend that alleged Straw had personally authorised the process.
Belhadj’s lawyers have served legal papers to Straw, referencing the article and “a number of documents which came to light after the fall of Colonel Muammar Gaddafi’s regime”.
In an interview with BBC Radio 4 last year, Straw claimed that the Labour government had never had any involvement with illegal rendition.
“We were opposed to any use of torture or similar methods.
“Not only did we not agree with it, we were not complicit in it and nor did we turn a blind eye to it,” he said in the interview.
According to The Telegraph newspaper, this is the first civil action of its kind against a senior ex-minister, and could result in Straw facing criminal prosecution.
Straw has so far not commented on the matter.