The chairman of the Bloody Sunday Inquiry made a last-ditch appeal today for anyone who can help the tribunal to come forward and give evidence.
Lord Saville made the fresh appeal as he signalled that oral evidence to the inquiry will be completed by Christmas.
Speaking ahead of Thursday's summer recess, Lord Saville said the inquiry would hear all the evidence of military witnesses in London, before returning to Derry in the autumn to hear the evidence of Sinn Fein MP Martin McGuinness and a number of Official IRA members.
Lord Saville warned that anyone who could help the inquiry, but had not done so, was doing a "great disservice" to the search for the truth of what happened on January 30th, 1972, when 13 civil rights marchers were shot dead by British soldiers in Derry. A 14th man died later.
"The process of seeking and taking evidence cannot, obviously, continue indefinitely," he said.
"I want, therefore, to urge those with whom the inquiry had been in contact, or who know that the inquiry has been trying to contact them, but who have not so far assisted the tribunal, to provide all the assistance that they can in the provision of information and, where relevant, evidence, and to do so as soon as possible."
Lord Saville said there were a number of areas in which evidence that ought to be provided was still absent.
"If significant evidence that could be given is not given, that will have two consequences," he said.
"Firstly, it will be a grave disservice to the search for the truth of Bloody Sunday, and , particularly, the relatives, who have so long sought it.
"Secondly, at the end of the day we shall have to reach a judgment on all the evidence that we have heard.
"But, in reaching that judgment, we may also have to take into account the fact, if it turns out to be one, that people who could have given evidence have chosen not to, since that fact may have a significance of its own."
The inquiry will resume at Methodist Central Hall in London on Monday, September 8th, and run for around six weeks, before returning to Derry after a short break, he confirmed.
"When we return to the Guildhall we shall be hearing the witnesses who could not be heard during previous sessions there, as well as those who have come forward since then, the Official IRA witnesses, Mr McGuinness and various others who we believe may be able to help us," Lord Saville said.
"If necessary we shall continue sitting until Friday, December 19."
PA