Journalist held over McGuinness leaks

The joint authors of a biography of Martin McGuinness have been arrested over the leaking of transcripts of telephone conversations involving the Sinn Fein chief negotiator.

Liam Clarke, Ireland editor of The Sunday Times, and his wife, Kathryn Johnston, were detained and a number of documents seized. A former Special Branch officer arrested on Wednesday is still in custody.

Mr Clarke was questioned by Special Branch three years ago over allegations he had broken the Official Secrets Act in a series of articles about a covert Army "dirty tricks" unit.

The editor of The Sunday Times called yesterday for the couple's immediate release. John Witherow said: "The account by our Northern Ireland editor, Liam Clarke, of phone taps in Northern Ireland poses no threat to national security. It merely embarrasses ministers. He and his wife should be released immediately from police custody."

The arrests follow publication of the transcripts used in the biography Martin McGuinness, From Guns to Government. The transcripts detail conversations between Mr McGuinness and Tony Blair's chief of staff, Jonathan Powell, and with the former Northern Ireland Secretary Mo Mowlam. Mr McGuinness was then education minister in the now suspended Stormont Executive.

Sinn Fein, which has protested to Downing Street, has accused MI5 of bugging the conversations and compiling the transcripts featuring Mr McGuinness, who has admitted once being the IRA's No 2 in Londonderry. Officers arresting the retired Special Branch officer also seized a computer and disks.

Earlier, the shadow Leader of the Commons, Eric Forth said: "If MPs are going to have their telephones tapped then we must know why and how and most important of all ... was it authorised by the Prime Minister?"