The Official IRA leader on Bloody Sunday will be unable to give evidence to the Saville Inquiry due to illness.
Soldiers shot 13 people dead in Derry on Bloody Sunday
Johnny White was expected to appear as the final witness when the tribunal resumes in Londonderry on Monday, but has been ill for the past few weeks.
He had been expected to say that the only Official IRA fire in the Bogside that day was a single round, 15 minutes before soldiers moved in.
He would have said the fire came a couple of shots after Jackie Duddy was killed at Rossville Flats.
The inquiry has been examining the events of 30 January 1972 when 13 civilians were shot dead by soldiers during a civil rights march in Londonderry. Another man died later from his injuries.
Counsel to the inquiry, Christopher Clarke, QC, is due to begin his closing speech on Monday and that is expected to last two days.
Evidence from politicians
His speech is intended to constitute an overview of the issues for the tribunal to decide; an overview of the evidence and an indication of a range of conclusions the tribunal might reach.
Only when Mr Clarke has finished that stage of the tribunal, will the three inquiry judges sit down to write their report.
Lord Saville of Newdigate and the Commonwealth judges accompanying him on the inquiry began their work in March 2000, and since then, more than 900 witnesses have given evidence to the tribunal.
The inquiry has heard evidence from leading politicians, including the prime minister at the time, Sir Edward Heath, civilians, policemen, soldiers and IRA members.
The inquiry has so far cost £130m. The final cost will be in the region of £150m.