The owner of the Sinn Fein car in which a bugging device was found last week has been seeking legal advice over invasion of privacy, party sources have confirmed.
The Ford Mondeo was one of a pool of cars used by the Sinn Fein president, Mr Gerry Adams, and other senior party representatives.
"The person is certainly taking legal advice at the moment. If there is a basis on which to take the British government to court, he or she will initiate legal proceedings. Then again, the British will no doubt invoke the `national security' excuse," a source said. He would not reveal the owner's identity, apart from saying the person was a Sinn Fein supporter.
The Sunday Telegraph has reported that the former Northern secretary, Dr Mo Mowlam, authorised the bugging of the car, but was not aware that it would be used by the Sinn Fein leadership.
The paper quoted security sources as denying that the car was bugged as part of a "freelance operation".
"Official operations have to be authorised by the office of the Secretary of State and this authorisation was forthcoming," a senior security official was quoted as saying.
The Northern Ireland Office refused to comment on the newspaper report apart from saying that it never commented on security allegations.