Sinn Fein president Gerry Adams has said anyone with information about the murder of Belfast man Robert McCartney should go to the police.
Robert McCartney was beaten and stabbed to death two years ago
Mr McCartney, 33, was beaten and stabbed to death outside a bar near Belfast city centre on 30 January 2005.
Mr Adams made the appeal after being challenged by the DUP and Irish justice minister Michael McDowell.
Mr McCartney's murder - allegedly by IRA members - placed huge pressure on Sinn Fein at the time.
The issue has resurfaced after the party voted to back the PSNI in a special meeting at the weekend, held just days before the second anniversary of the killing.
In 2005, Sinn Fein refused to explicitly tell people to contact the PSNI, but Mr Adams now says: "Anybody who has any information about the McCartney killing should give it to police."
He added: "Michael McDowell should not be setting tests for anyone - this is the minister who refuses to put into place in the other jurisdiction on this island, the type of accountability and mechanisms that are in place in this one.
"Mr McDowell, like Ian Paisley, is in no position to lecture or to give tests or to in any way put preconditions upon Sinn Fein."
As police were issuing a new appeal for information on Tuesday, the second anniversary of the killing, Mr McCartney's sister Catherine said his death should be a "litmus test" of Sinn Fein's support for policing.
"Sinn Fein members (in the bar) refused to speak to police. They had a nonsense of talking to third parties like priests, but that was fruitless. Police are trained to take statements, not priests.
Mr McCartney, a father-of-two, died the day after he and his friend Brendan Devine were attacked - allegedly by IRA members - inside Magennis' Bar in May Street and then in Cromac Square.
One man has been charged with his murder, and another with the attempted murder of Mr Devine.
Sinn Fein said it had suspended a number of its members after the killing, and Mr Adams previously said he supported the family's campaign for justice.