Discovery of the car bug sent disruptive ripples through the peace process, and Mr Adams cited it as evidence that security and intelligence elements were intent on undermining the Good Friday Agreement and the new institutions of government in Northern Ireland. "I feel shafted by the discovery of this," Mr Adams declared.
Tony Blair, responding to a Commons question, would say only: "I never comment on security allegations, I don't intend to do so now."
On a more welcome note for the authorities, the illegal Ulster Freedom Fighters, one of the two main loyalist paramilitary groups announced that, like the IRA, it would make contact with Canadian General John de Chastelain's International Commission on Decommissioning. Johnny "Mad Dog" Adair, recently released from prison, was among a number of interlocutors named yesterday.
Although no one expects any early act of decommissioning by loyalists, the appointment of interlocutors was seen as an encouraging sign.
The bugging development, however, was viewed as being damaging to the unprecedentedly harmonious relations which have developed between republicans and the Government in recent years. Although no one was prepared to confirm or deny that the apparatus was the work of the intelligence services, either with or without ministerial approval, the general assumption in Belfast was that it had indeed emanated from the authorities.
Even if, as it was said yesterday, Mr Adams and Martin McGuinness did not use their bugged Ford Mondeo for many journeys to the Northern Ireland peace talks, the fact that they used the car much more frequently for meetings with IRA high command made the device worth its weight in gold.
Hearing Mr Adams and Mr McGuinness discussing how they would deal with their IRA counterparts must have been like manna from heaven for British officials. Intelligence officers - and their ministers - would have enjoyed an insight into republican thinking at a critical moment in the talks, when they needed to know whether Sinn Fein and the IRA were serious about decommissioning weapons, or were simply stringing the Unionists along. Such information could have persuaded Tony Blair "to go the extra mile for peace".
It was by no means a new strategy. MI6 tried to bug Soviet leader Nikita Khrushchev when he visited Britain in 1956. That was scuppered when MI6 frogman "Buster" Crabbe died mysteriously under the President's warship. And during the Lancaster House talks over the future of Rhodesia in 1979, British intelligence secretly taped the other side's private conversations.
Nor is it the first time that Sinn Fein has discovered bugging devices during the peace talks. Gerry Kelly, a Sinn Fein official, claimed a house used by his party in the early days of the peace process was bugged.
The matter of "how" the bugging was done is as complex as the "why" is simple. The tracking and listening device found in the car used by Mr Adams was described as "very sophisticated" by a former military intelligence officer with experience in Northern Ireland. He had little doubt that it was the work of British intelligence.
It appears to consist of a "geo-positional satellite", or GPS, tracking device and a radio to transmit anything said in the car. "These devices are available separately but to put them together this way is a very clever package," he said.
The year-old Mondeo belongs to an associate of Mr Adams and Mr McGuinness and is one of a number the two Sinn Fein leaders use. The device was carefully wired up in the bowels of the car. Whoever installed it must have taken many hours and carefully refitted the car's innards. The microphone was wired into the middle of the roof of the car.
There are suggestions that the Mondeo was "borrowed" overnight by the security forces to fit the device. However, the former military intelligence officer doubts this, pointing out that taking a car known to be used by Mr Adams for such a length of time would be extremely difficult. He suspects that the device might have been fitted into the car before it was delivered to its new owner a year ago. According to Mr Adams, the device was designed to switch on with the car ignition to prevent it draining the car's battery.
Technical experts working for Mr Adams said after a close look at the equipment that the main box had an output of 20 to 30 watts. The listening device could be turned on or off remotely through an input aerial. The GPS tracking system had rechargeable batteries wired to the car battery. According to Sinn Fein, "All of this was done in such a way as to make it impossible for anyone carrying out repairs on the vehicle to find the device."
It is likely the device was made at a secret British intelligence base near St Albans which specialises in covert devices of this type, according to intelligence sources. The GPS device would have sent messages via satellite to a British intelligence base in Northern Ireland, probably in Lisburn.
It is similar to GPS navigation equipment used by ocean-going yachts for navigation and by security companies like Group 4 to track the movements of their armoured cars. Journeys in Sinn Fein's car could be watched on a special screen. The Defence Evaluation and Research Agency recently offered these type of screens for sale at a recent security show.
The co-ordinates of each trip could be stored on a computer which would automatically search for patterns - regular journeys at regular times. As the car travelled around the computer would instruct the hundreds of cameras placed around the province at border crossings to record its journey. How the radio transmitter worked is not yet clear. . Similar tracking and listening devices are believed to have been used on the UK mainland, mostly by MI5 tracking drug barons. Last year, Tommy Adams of the North London crime family was jailed for smuggling tons of cannabis, largely on the basis of conversations in a taxi he used which were recorded using a less sophisticated but similar device.
The irony of the matter was that if this was a British intelligence operation it will have been legal. The Northern Ireland Emergency Act 1996 gives permission to the security forces to do almost anything they like including burgling and bugging.
Mr Blair's official spokesman said: "In common with previous governments, we don't comment on intelligence issues and we do not comment on allegations such as this."
However, this was not the case during a previous bugging controversy, when Sinn Fein claimed that in a Stormont office allocated to them they had detected a positive signal from a photocopier, using a scanning device. On that occasion, the Conservative minister Michael Ancram said he wished to state categorically that the room was not "monitored by or on behalf of the British government".
In April 1998, Sinn Fein produced a video of what it said was a bugging device in a house used by Gerry Kelly, one of its senior negotiators. Security sources privately blamed the discovery of the device on Mo Mowlam when she was secretary of state Northern Ireland.Reuse content