Manningham-Buller told a closed meeting of the parliamentary intelligence and security committee before Christmas that MI5 had planted a sophisticated listening device at the head offices of Sinn Fein at Connolly House in Andersonstown, west Belfast.

In the security service’s first formal acknowledgment of the bugging operation, MI5’s director-general told the committee, which monitors Britain’s intelligence services, “they [Sinn Fein officials] had to almost shred the office to find it”.

The 5ft device was found last September hidden in a floor joist at the headquarters of the party, which is the IRA’s political wing.

Sinn Fein said at the time that two live microphones were found, one pointed towards the upstairs office and the other at a downstairs conference room.

When the bugging was disclosed, Downing Street and the Northern Ireland Office declined to discuss the matter. But the find embarrassed Tony Blair who only days later had to face Adams, the party president, and other Sinn Fein officials for talks.

Adams described the bug as “a serious act of bad faith” and “a violation of human rights”. He added: “The British make it very, very hard to make peace when this goes on . . . this is a violation of the peace process.”

Manningham-Buller’s admission of the MI5 bugging operation comes as the peace process is under renewed threat because of the IRA’s alleged involvement in the £26.5m robbery at the Northern Bank last month.

Hugh Orde, the chief constable of Northern Ireland, has said that “intelligence” has linked IRA leaders to the crime.

The Connolly House bug was the latest in a series to have been found in property used by senior Sinn Fein and IRA members.

Just a week earlier, a listening device had been found at the home of Paula McManus, who works in Adams’s west Belfast constituency offices. She is not suspected of any wrongdoing but her home was targeted because of her friendship with Martin Lynch, the adjutant-general of the IRA. He in turn is said to have met Bobby Storey, the IRA’s director of intelligence, at the flat.

That bug consisted of a microphone, six battery packs and a transmitter. It was concealed in the beam in the loft of the flat, which could be accessed from a communal area at the front of the building.

Adams and Martin McGuinness, the party’s chief negotiator, blamed Paul Murphy, the Northern Ireland secretary, for authorising the surveillance operation.

In 1999, a sophisticated listening and tracking device worth £20,000 was found built into a car owned by Lynch. Adams and McGuinness said the car had been used to take them to meetings with the IRA leadership. The bugging occurred during the review of the Good Friday agreement by George Mitchell, the former US senator.

The intelligence and security committee was set up by an act of parliament in 1994 as a watchdog for the intelligence services.

It is chaired by Ann Taylor, the former Labour chief whip, and comprises senior MPs and one member of the House of Lords. It reports directly to the prime minister on the work of MI5, MI6 and GCHQ, the government’s eavesdropping agency.

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