Sinn Féin's chief negotiator, Mr Martin McGuinness, yesterday refused to tell the Bloody Sunday Inquiry the locations of IRA arms dumps and of an IRA "safe house", saying that for him to do so would be "a gross act of betrayal".
On the first day of his evidence to the inquiry in Derry's Guildhall, Mr McGuinness clashed with the tribunal's chairman, Lord Saville, who accused the MP of putting his "duty of honour" above the desire of the families of the victims to discover the whole truth about the events of Bloody Sunday.
Mr McGuinness, who rejected Lord Saville's assertion, was giving evidence on the 390th day of the inquiry into the killing by paratroopers of 13 civilians and the wounding of 13 others during an anti-internment march in January 1972.
As he was taken through his 113 page statement by the inquiry's counsel, Mr Christopher Clarke QC, Mr McGuinness gave a breakdown of the structure of the Provisional IRA in Derry at the time of Bloody Sunday in January 1972.
However, the witness initially refused to tell the inquiry if he had ever been a member of the Official IRA, the locations of IRA weapons dumps, the location of an IRA "safe house" and when he became officer commanding the Provisional IRA in Derry.
The chairman said he could not understand Mr McGuinness's refusal to answer the questions, given the MP's anxiety to help the tribunal to establish the full truth about Bloody Sunday.
"What we shall do now is to rise for a few moments, and I would ask you to consider answering these questions, because if you do not, two things will happen. Firstly, you are depriving us of the opportunity of discovering the full facts and matters relating to the events of Bloody Sunday, and secondly, of course, it will be suggested in due course that the reason you are not answering these questions is that you have got something to hide," Lord Saville said.
After a short adjournment, Mr McGuinness then confirmed he had been a member of the Official IRA for several weeks before he joined the Provisional IRA early in 1971. He said that within two weeks of Bloody Sunday he had become OC of the Derry command of the Provisional IRA".
However, he said he would not give the inquiry details of IRA arms dumps and a safe house because there was a republican code of honour. "To do so would have been a gross act of betrayal, and I just could not do that," he said.
"I understand the need for the tribunal to have that information, but this is a deeply personal thing for me. For me to give the location of these buildings and in doing so identifying the people who own these buildings would be a gross act of betrayal and I just cannot do it," he added.
Lord Saville told Mr McGuinness he was "bound to say I understand your answer as being that you feel that your duty of honour overrides the desire of the families for the tribunal to discover the whole truth about the events of Bloody Sunday".
Mr McGuinness replied that that was not his position. He also said about three-quarters of the Provisional IRA's command structure in Derry on Bloody Sunday were still alive. He said several of them had sought him out about giving evidence to the inquiry and he had told them it was a personal decision for each of them, although he would be "most happy" if they came forward.
"I think also people need to remember that practically all the people of whom we are now speaking have not been members of the IRA, to the best of my knowledge, over the course of many decades, so they are in employment, they have families, and it was my view that this was a decision they had to make themselves," he said.
Mr McGuinness said orders had been given to Provisional IRA members not to engage in violence with British soldiers on the day. He confirmed, however, that in the aftermath of the shootings the Provisional IRA had fired "symbolic shots" at British soldiers positioned on the city walls overlooking the Bogside.
He described allegations that he was involved in the planning of an aborted nail-bomb attack on Bloody Sunday as "a bucket full of lies". He also said he refuted "with all the strength that I can" allegations that he was armed with a Thompson sub-machinegun on Bloody Sunday.
Mr McGuinness told the inquiry's counsel that he had not "received the blessing" of the Provisional IRA to give his evidence to the hearing.
He apologised for ignoring four requests from the inquiry in 1999 to make a statement. He said that, if he had made a statement then, it could have caused legal and political problems and difficulties for the peace process.
His evidence continues.