The Northern Secretary, Mr Peter Mandelson, has warned that if it is established that the IRA murdered Edmund McCoy over a week ago, it could have a direct impact on future prisoner releases.
Reports that senior security sources believe that the IRA was behind the murder of Mr McCoy in Dunmurry, near Belfast, on May 28th prompted unionist calls to have Sinn Fein ministers expelled from the Executive.
The developing controversy surrounding the killing is serving to add to the current political tensions. Last night the Taoiseach, Mr Ahern, and the British Prime Minister, Mr Blair, met for a working dinner in Downing Street to focus on the difficulties, particularly over policing.
London and Dublin described the meeting as a stock-taking exercise following the restoration of the institutions of the Belfast Agreement.
Mr Ahern is understood to have repeated his assertions in the Dail yesterday that the Patten report on policing must be fully reflected in the Police (Northern Ireland) Bill when it is finally completed.
Mr Mandelson said he was aware of the speculation that the IRA killed Mr McCoy, a known drugs dealer. Directly after the murder some nationalist and unionists politicians insisted the IRA was responsible.
On Tuesday, the BBC cited security sources making the same claim, raising the possibility that eventually the RUC Chief Constable, Sir Ronnie Flanagan, may adjudicate that the IRA murdered Mr McCoy.
"An intensive police investigation is now under way," Mr Mandelson said yesterday. "If evidence becomes available in the course of that investigation that any paramilitary organisation now on ceasefire was responsible for this crime, I would take this very seriously indeed," he added.
"It would have a direct impact on my assessment of the ceasefire and therefore potentially on further prisoner releases," said Mr Mandelson.
At present, about 50 IRA members are in prison in the North. All are due to be let out under the release scheme. Were Mr Mandelson to halt releases, it could result in the IRA withdrawing its statement pledging to put its weapons verifiably beyond use.
Last August, the former Northern secretary, Dr Mo Mowlam, was undermined when she accepted that the IRA had not broken its ceasefire, after it allegedly murdered Charles Bennett. The DUP Minister for Social Development, Mr Nigel Dodds, and Ulster Unionist Party MP Mr Jeffrey Donaldson yesterday called for Sinn Fein's two ministers, Mr Martin McGuinness and Ms Bairbre de Brun, to be expelled from the Executive.
Sinn Fein however described the claims of IRA involvement as "spurious". Belfast Sinn Fein councillor Mr Michael Browne said that RUC sources were now accusing the IRA, after at first "effectively dismissing the possibility of republican involvement" in the murder.
