The IRA army council should release former members from their oath of secrecy so they can give evidence about what they did on Bloody Sunday, the inquiry was told yesterday.
Mr Eamonn McCann said the families of victims felt that IRA members who have not come forward "are in effect polluting the truth about Bloody Sunday by not clearing up what they were doing".
Continuing his evidence, the journalist and author agreed he may have had a part in the decision last month by some former members of the Official IRA to contact the tribunal.
Following an appeal by counsel for the families, he had spoken to a number of people "and I put it to them in robust terms that many people in Derry would not understand if they did not come forward".
In reply to Mr Arthur Harvey QC, for a number of families, Mr McCann said he believed the only people who could provide the tribunal with accurate reliable information on IRA activities on Bloody Sunday were members of the IRA.
On the questioning of civilian witnesses about IRA activity, he said some counsel might have neglected the fact that "these are . . . were oath-bound, clandestine, secret armies".
He said no one other than the members of these organisations could give credible accounts of what they did. "I believe that they ought to come forward," he said. "The members of the Official IRA ought to have come forward much earlier than they have done; I believe that members of the Provisional IRA should have come forward long ago and given their evidence to this tribunal and that they should do so now."
The victims' families were aware that if Provisional IRA members did not come forward and give their account, it was inevitable "inferences adverse to them might be drawn".
However, common sense indicated there would be a problem for any member or former member coming to the inquiry to tell all that he or she knew about IRA activities on Bloody Sunday.
"These people, by definition, because they are members or were members of the IRA will have taken an oath to do no such thing ever - never to divulge anything about the activities of the organisations." He said he believed that members or former members would be helped to come forward "if the current army council of the Provisional IRA were to release them, as it were, from their solemn undertakings of secrecy". This would be unprecedented, but the organisation had taken unprecedented decisions in recent years. They should take this one too, and take it now.
He agreed there had been outrage in the community that there was other shooting on Bloody Sunday, because it could give apparent justification to the British army for the deaths of innocent civilians.
However, he said, almost everyone in the community believed that nothing republicans did on the day affected events "or could rationally be construed as having provoked the killing and wounding of 27 people".
Mr McCann confirmed he was not prepared at the moment to name anyone he knew to have been involved in the shooting. Asked if, as a friend of many of the victims' families, he was prepared to assist them in getting the individuals to come forward, he replied: "I will do what I can."
He also told counsel the questioning of civilian witnesses who had been asked to reveal names had created apprehension among potential witnesses. It was felt they were being pressurised into becoming, in effect, informers. This ran counter to the ethos of their community, and, more than that, knowledge was being ascribed to them which they did not have.
"Many people are troubled in Derry about what appears to be the balance, of the tone and pattern of questioning at the inquiry in relation to this matter." The chairman, Lord Saville, said they were aware of these apprehensions and the method they were forced to adopt was unsatisfactory, but they had a duty to try to find the whole truth "and if that is the only method open to us, we must take it".
At the outset of yesterday's hearing, Lord Saville announced that, because the tribunal was concerned not to prejudice genuine claims for anonymity, it had decided not to seek from Mr McCann, for the present at least, the names of those who might have been involved with the IRA on Bloody Sunday.