LONDON - Britain will hold a formal inquiry into whether its government and spy agencies colluded in the torture of terrorism suspects overseas, a potentially embarrassing probe that could affect intelligence gathering and upset ties with allies including the United States.

The government confirmed Friday that Foreign Secretary William Hague had authorized a long-promised judge-led inquiry into allegations that British officials were complicit in the mistreatment of suspects held by the United States, Pakistan, and others.

A total of 12 men have filed lawsuits against the British government alleging officials were involved in their purported torture. Police are investigating the actions of two intelligence officers from the MI5 and MI6 spy agencies.

Campaigners have long pressed for an inquiry supervised by a judge to examine Britain's policy on torture. Their call was supported by the Conservative and Liberal Democrat parties, which last week formed Britain's new coalition government following an election in which no party won a majority.

"Both parties in the coalition said they wanted that, now what we're working on is what form that should take," Hague told the BBC late Thursday. Britain's Cabinet Office confirmed Friday that an inquiry would take place "as soon as is practicable."

The inquiry will be one of two separate reviews into how Britain pursued terrorists. A High Court judge ruled Friday that a series of inquests into the deaths of 52 commuters in London's 2005 transit network bombings would examine possible intelligence failures.

It hasn't been determined whether part, or all, of the torture inquiry would be held in public, or whether it would have the power to compel witnesses to attend. The inquiry will be led by a senior judge - considered to be more independent than government officials - though no one has yet been appointed.

Like Britain's inquiry into the Iraq war, the inquiry chief is likely only to make recommendations about future conduct, and not have the power to assign criminal liability or apportion blame.

Conservative lawmaker David Davis, who has campaigned for an inquiry, said that it must have "full access to all people and papers, in all security classifications, both at home and abroad."