A man has been arrested over the murder of Belfast man Robert McCartney.
The man went to Musgrave Street Police Station in Belfast with his solicitor but a PSNI spokeswoman said they would not be commenting on his identity.
Last night the IRA issued a statement saying it had expelled three of its members over the killing, two of them senior figures.
It said one of the three IRA members who were thrown out had gone to a solicitor immediately after the incident to make a statement on his actions on the night of the killing.
The other two members were advised "in the strongest terms possible" to come forward and take responsibility for their actions.
It was unclear if any of the three former IRA members had gone to the police station in Belfast today, or if it was another person.
The family of Mr McCartney today called on everyone who was present when he was murdered in a Belfast City centre bar on January 30th to turn themselves in.
In a statement, they welcomed the IRA's expulsions but asked for others involved in the incident to turn themselves in.
Insisting a trial must take place, the family said: "It is, however, only when all those involved, that is those IRA members and others, regardless of how small a part they played in the murder and their subsequent clean and cover-up operation, have handed themselves in and are charged, tried and convicted by the courts will we as a family be able to bring closure to this horrific ordeal and begin to grieve for Robert."
Earlier today Sinn Fein leader Gerry Adams piled pressure on republicans involved in the incident to come forward.
Speaking in Cork this morning, Mr Adams said: "The IRA acted, I think, on its own counsel on all of this."
"I think there are other issues involved but I want to make this very, very clear.
"Had I found myself in Magennis's Bar and was caught up in these dreadful events, I would now be making myself available to the court as the McCartney family have asked.
"I would say that very, very conscious of the reservations which people may have about such courses of action but I just think the situation is so serious that any self-respecting republican who got caught up in all of this because of drink or because of whatever else occurred, they do have a responsibility to redeem themselves.
"They won't bring Robert McCartney back but that is what I would do if I was there."Speaking on the by-election campaign trail in Co Kildare today, the Taoiseach, Mr Ahern said the IRA statement was a reaction to pressure put on republicans.But he added: "The real issue is will people be convicted". He said the only way this will happen is if people co-operate with the authorities. "And the authorities in this case are the PSNI," he said. Mr Ahern called for "real prosecutions and real court sentences on the issue".