Published Wednesday, 25 April 2012
The deputy First Minister questioned Mr Hurst’s credibility. (© Pacemaker)
Former intelligence officer Ian Hurst, also known as Martin Ingram, also claimed that Mr McGuinness did not leave the IRA in the 1970s.
Evidence given in private session last week is now being read to the tribunal, which is investigating the 1989 murders of two senior RUC officers in an ambush on the Irish border.
On Tuesday it heard claims from Mr Hurst that a "Mr McGuinness" was involved with the IRA's Northern Command as it sanctioned the shootings of Harry Breen and Bob Buchanan.
A statement from Sinn Féin said the deputy First Minister rejects the allegations.
It added: "This individual who uses a variety of names including Martin Ingram has no credibility.
"By his own admission he is part of a British security apparatus which played a very negative and malign role in the conflict, including widespread involvement in collusion."
The tribunal was also told that the high-ranking double agent known as Stakeknife was Freddie Scappaticci and that he was also in the IRA's Northern Command and would have known about the RUC murders.
A redacted version of Mr Hurst's evidence said: "It was authorised at Northern Command and Mr McGuinness was involved as OC (Officer Commanding).
"He (Stakeknife) was their most skilled investigator of suspected informers and he acted as one of their executioners."
The tribunal is investigating allegations of Garda collusion over the IRA murders of officers Breen and Buchanan, just north of the border in Co Armagh, 23 years ago.
They had been returning from a meeting with senior garda in Dundalk in the Republic of Ireland when they were attacked. The Provisional IRA claimed the murders.