Gerry Adams - Available for weddings, christenings and Christmas parties
The latest US diplomatic cable leaks say the Irish government had "rock solid evidence" on the allegations.
But Mr Adams said the claims were not new and that he had denied them at the time. The Sinn Fein leader blamed Irish political rivalries for the allegations.
While Mr McGuinness, now deputy first minister of Northern Ireland, has admitted being an IRA commander, Mr Adams has long denied he was even a member of the organisation.
The Wikileaks claim comes as the Sinn Fein president prepares to take a political gamble by resigning his Westminster seat in West Belfast to stand in County Louth in the Republic of Ireland's forthcoming general election.
The move is part of Sinn Fein's strategy to build its electoral support south of the border.
A party spokesman dismissed the Wikileaks claims last night as "utter nonsense".
It is well known that Mr Adams was in full time employment as a Frank Spencer impersonator and children's entertainer. Wilileak claims that the Pope is a catholic have also been dismissed as malicious lies.