The claim, which will be made in a new documentary made by Taylor, 'The Age of Terror,' has been strongly denied by Mr. McGuinness, who described it as "a securocrat fantasy."

Eleven people were killed in the bombing in November 1987 when a huge bomb exploded at the cenotaph in Enniskillen during a Remembrance Day commemoration.

In the programme, Mr. Taylor who has previously made documentaries about the IRA, loyalist paramlitaries, and the British Army in the North, claims that Mr. McGuinness was a senior figure in the IRA's Northern Command - the body responsible for co-ordinating IRA operations in the North.

Mr. Taylor claims that three separate security sources - from both sides of the Border - told him Martin McGuinness was responsible for the Northern Command.

"I have been told that three units were involved therefore it must have been co-ordinated by the IRA's Northern Command. Intelligence sources on both sides of the border told me that the leading figure in the Northern Command was Martin McGuinness.

'Independent sources'

"Three sources totally independently confirmed that Martin McGuinness was a leading figure in the Northern Command," he claimed.

The British journalist also said he put the allegations to the Deputy First Minister who denied them.

"I spoke to Martin McGuinness and he categorically denied two things; that he was on the Northern Command and that he knew about Enniskillen," he said.

Mr. Taylor admitted the allegations would be difficult to prove as his sources are secret.

"It is hard to prove. These things don't come to court so you have to make your own judgement," he said.

Mr. McGuinness dismissed the claims saying; "The allegations made in this programme are completely false and are entirely based upon untrue briefings from faceless individuals within the intelligence apparatus long hostile to Sinn Féin."