I'm in danger says bugging detective

In an extraordinary twist to the scandal, former sergeant Mark Kearney said he became afraid after the secret bugging operation was made public."I believe it puts my life and safety at risk," he claimed.

Mr Kearney alleged that he was ordered to bug Mr Khan and came under "significant pressure" from the Metropolitan Police to go ahead despite his ethical objections.

Speaking to the BBC after his role was revealed he said: "I'd like to say that I'm shocked and disgusted by this leak to the media. I'd also like to say I am quite prepared to co-operate with any inquiry."

Mr Kearney's allegations have raised major questions over whether the Yard deliberately set out to eavesdrop on Mr Khan, a former human rights lawyer who is now a rising Muslim Labour MP.

His role was detailed in a court statement made while fighting unrelated charges of misconduct, which include leaking details of police operations to a local reporter friend.

The bugging of Mr Khan took place when the MP visited Babar Ahmad at Woodhill Prison in 2005 and 2006. Listening devices were planted in six desks to ensure that Mr Ahmad's visitors could be overheard.

Until now it was widely assumed that Mr Ahmad was the only target of the operation, which was not passed upwards to ministers for approval. However, Mr Kearney claimed that he questioned the propriety of recording an MP and was ordered to get on with it.

The former Thames Valley force sergeant, who was working in Woodhill Prison at the time, said: "I did record the visit but never thought it justified in these circumstances."

The Metropolitan Police said it was not prepared to discuss matters of national security.

Former Met assistant commissioner Sir David Veness was named as giving authorisation for Mr Ahmad to be bugged as early as 2004.

The Daily Mail said Sir David, who retired in 2005, was thought to have informed then Met commissioner Sir John Stevens about the operation but it would have been less controversial at that time because Mr Khan was not an MP. It is not clear when current Met chief Sir Ian Blair was told about the operation. The affair took a new twist today when it emerged that government officials were alerted to the situation months ago but did not tell ministers.

A Ministry of Justice spokeswoman admitted: "Ministry of Justice officials became aware in December of issues concerning visits to Woodhill Prison by Sadiq Khan MP."

That begged the question of why Justice Secretary Jack Straw was kept in the dark until the affair was splashed over a Sunday paper at the weekend. It follows the curious incident of a letter going missing in the post that was sent by Tory shadow home secretary David Davis to warn Gordon Brown about the allegations.

Mr Davis said it was "beyond belief" ministers were not informed. "It is now becoming apparent that the Government did know about this very serious issue - at the time I wrote my letter," he said.

"It is beyond belief that the department would not flag up to a minister that the Wilson Doctrine had been broken within the department." The Wilson Doctrine is a 44-year-old ban on bugging MPs' telephones.

Writing in today's Evening Standard, Mr Davis says ministers have badly failed to explain the affair.

"The most worrying feature of the Sadiq Khan case is the cavalier way in which the rules were broken and the casual nature of the government's response," he writes.

Lib Dem home affairs spokesman Chris Huhne said it was an "appalling comment" on Mr Straw's ability to run his department.

Mr Straw announced an inquiry into the affair yesterday, headed by Chief Surveillance Commissioner Sir Christopher Rose. It will report within a fortnight.

He is now being urged to widen it to include other allegations that prisons were routinely bugged by the police.

Human rights lawyer Imran Khan said: "It seems to be an unwritten understanding, certainly at Belmarsh and Woodhill prisons, that inmates feel that those conversations are being monitored. Certainly things that have happened in the course of my career recently indicate that that might be the case."

Downing Street said the Wilson Doctrine would have to be reviewed after the case exposed a glaring loophole in it. It became apparent police buggings of an MP's rooms or private car were not covered by the ban on intercepts - yet the same operations are banned if carried out by MI5.

Babar Ahmad is fighting deportation to the US for trial over allegedly running a website to raise funds for Chechen separatists and the Taliban. He is a childhood friend and a constituent of Mr Khan.

Home Secretary Jacqui Smith and the deputy chief constable of Thames Valley force will be questioned by the home affairs select committee over what they knew.