Two Sinn Fein members have been thrown out of the party over the Robert McCartney murder, the party's president Gerry Adams has revealed.
Another four who were also in the Belfast bar on the night of the IRA killing have quit after refusing to make statements.
The six were among 12 suspended by the party leadership under pressure to act by the dead man's sisters.
Tonight the sisters challenged Mr Adams to declare whether the ousted pair were among the men suspected of direct involvement in the January 30 pub brawl murder.
When asked a Sinn Fein spokesman said: "I wouldn't know. It's up to the IRA to name who they expel." In the aftermath of the attack, the Provisionals said they had thrown out three of their men.
Catherine McCartney said tonight: "Gerry Adams is confusing matters more than clearing them up. "He hasn't addressed any of the issues the family wanted him to address, apart from saying he would make public the findings of an internal investigation."
Mr McCartney's sisters and partner Bridgeen Hagans have fought a relentless campaign to bring the killers to justice. They have been to the White House and the European Parliament in a bid to pressurise the chief suspects into court.
But even though the family claim the republican movement has been shielding the murderers, Mr Adams insisted the party fully backed their demands for the murder gang to face trial and was doing all it could to help.
He said: "I called on those responsible to come forward and admit their responsibility for this horrendous murder. They have refused. "I also called on everyone who was in the vicinity of Magennis' Bar to provide full and frank statements. "Because Sinn Fein takes this matter so seriously, we suspended the 11 members of the party who were in the bar that night and the one who later arrived on the scene.
"They were suspended, without prejudice, while the party establishes whether they complied with the call by party leaders for everyone to provide a full and frank statement.
"Of the 12 members suspended four resigned and two were expelled for refusing to follow this instruction. "As we have already stated publicly, the other six remain suspended pending a report to the party's Ard Chomhairle (National Executive). The conclusions of this process will be made public."
But the West Belfast MP's response failed to satisfy the McCartneys, who had presented a series of demands, including why Sinn Fein did not immediately approach the family, its reason for initially describing the murder as part of a growing knife culture, and at what stage the party realised SF election candidates were in Magennis' that night.
They also wanted to know when the party launched its internal investigation, its purpose, and timescale. Police Ombudsman Nuala O'Loan's office, which has offered to take witness accounts to aid the investigation, could not confirm allegations that statements from Sinn Fein members have not been signed.
It is understood, however, that between 10 and 20 statements have now been received by the Ombudsman's staff.
PA