Former members of the Official IRA could face prosecution for their actions on Bloody Sunday.
A file on one former member of the Official IRA has been sent to the North's Public Prosecution Service (PPS) by the Police Service of Northern Ireland (PSNI).
A second file in relation to another former IRA member may also be sent to the PPS.
Thirteen people died when members of the British army’s Parachute Regiment opened fire on civil rights marchers in Derry in January 1972.
A fourteenth victim died later.
In a letter sent to the families of the victims by the PPS, it said it has received additional files from the PSNI and one of these related to a former member of the Official IRA.
“The suspect is not a soldier and is not alleged to have shot any civilian,” the letter said.
“The file relates to alleged Official IRA activity on Bloody Sunday.”
The 2010 Saville Inquiry into Bloody Sunday concluded the British army fired the first shots.
A member of the Official IRA told the inquiry they had shot at soldiers in retaliation to the shooting of two protestors.
In the letter the PPS said it expects some further material from people who have not previously given evidence to the PSNI and that statements are due to be recorded which may result in one further Official IRA suspect being reported to the PPS.
“We anticipate that this will be the final suspect reported,” the letter said.
The PPS also said it was considering whether there should be any investigation into allegations of perjury by accused soldiers giving evidence to the Saville Inquiry.
A murder investigation was launched by the PSNI after the Saville Inquiry report said the people who were killed or injured on Bloody Sunday were innocent.
Investigation files were passed to the PPS in December 2016 and earlier this year it was revealed the PPS was considering bringing charges against 18 soldiers in relation to Bloody Sunday.
In the letter,the PPS said it hoped it would be able to make a final decision on whether to recommend prosecutions that within six months.
John Kelly, whose 17-year-old brother Michael was killed on Bloody Sunday, said he believed the investigation of the Official IRA was a distraction tactic.
“This is supposed to be a murder investigation carried out by the PSNI,” he said.
“The Official IRA themselves admit that they fired off shots, but they did so in response to people being mown down on the streets by the paratroopers.
“They weren’t responsible for killing anyone.
“I know the PSNI have to follow the evidence wherever it goes, but the underlying question is why are they doing this?
“I don’t see the point, apart from it being a distraction and perhaps lengthening the time it takes for this investigation and for the PPS to come to a decision regarding prosecutions.
“The Official IRA came in good faith at the request of the families to give evidence at the Saville Inquiry to enable the full story of what happened on Bloody Sunday to be told. Now we hear they may be prosecuted?
“They witnessed murder and they retaliated. They were not responsible for it.
“It’s a murder investigation, and it should be investigating murder,” he said.
Temporary Detective Superintendent Ian Harrison, from the PSNI's Legacy Investigation Branch confirmed a number of files have been submitted to the PPS for consideration.
“As such, it would be inappropriate to comment further at this time,” he said.
