Mr Martin McGuinness of Sinn Fein has told the Bloody Sunday inquiry lawyers that the Provisional IRA in Derry agreed to a request from civil rights representatives that IRA members should stay away from the march and be unarmed, it was learned last night.
Mr McGuinness's formal statement to the inquiry, in advance of his oral evidence, has now been completed and circulated to legal teams for all parties at the inquiry.
It is understood that he confirmed in it that on Bloody Sunday, at the age of 21, he was the adjutant or second-in-command of the Derry Command of the IRA. In the document, on which he will be cross-examined when he gives evidence in coming weeks, he outlines an approach made to the officer commanding the Derry Provisionals by people representing the Civil Rights Movement three days before Bloody Sunday.
He says that these people asked the IRA not to be present with arms on the march in order to facilitate its peaceful purpose.
Mr McGuinness also says he was asked by the OC for his opinion, and he agreed that the request should be granted.
He also says he was instructed at that time to issue orders to all volunteers not to engage militarily with British forces, in order to ensure that the march would pass off peacefully.
On the following day, Saturday, he spoke with the command staff and all volunteers and they immediately accepted the decision.
There was one exception, however.
Mr McGuinness reveals that two units of the IRA were instructed to remain on patrol, "armed and vigilant" in the Creggan and Brandywell areas of Derry.
This was because the IRA feared that the British army might take advantage of the huge Bogside march to enter and take over these areas.
The eight people in these two units were the only IRA armed units in the so-called Free Derry area for the duration of the march, he says in his statement.
Mr McGuinness also strenuously denies an allegation by an alleged British army informer, who is believed to have claimed that he heard him admit to firing "the first shot" on Bloody Sunday. He describes this allegation as "a concoction, rubbish and a blatant lie".