A man who claimed Sinn Féin's Mr Martin McGuinness distributed nail bombs on Bloody Sunday is due to take the stand at the Saville inquiry today.
Mr Paddy Ward, a republican living in protective custody, will be questioned by the inquiry about what he alleged happened when 13 people were shot dead by British Paratroopers in Derry in January 1972.
Central to his testimony will be the claim that Mr McGuinness, who was the IRA's number two in the city at the time, handed out explosives to members of the paramilitary group.
The Sinn Féin chief negotiator is expected to deny the allegations when he gives evidence - once the tribunal returns to Derry's Guildhall, from London later this month.
Until last week, Mr McGuinness was the only self-confessed IRA man to have come forward to the inquiry.
But five others who admitted being members of the Provisionals on Bloody Sunday have also now made statements, with a sixth expected later.
PA