The family of Robert McCartney today asked the driver of a blue car to come forward in their efforts to bring the Belfast man's killers to justice.
As police made a new appeal over the vehicle they believe was stopped at traffic
Robert McCartney's sisters
lights near the scene of the Belfast city centre stabbing, the dead man's sister Paula insisted the pain and trauma would not ease until the gang responsible were all caught.
On the first anniversary of the father-of-two's killing, she said: "Our grieving process has been hindered by the fact that the people who took his life for no reason at all have not been held to account.
"We also believe if we had some closure by these people being brought to justice it would help in the grieving process of this family.
"We are practically begging people, please if they have any information at all, release it and put this family out of the misery they have been suffering for a year.
"The blue car is very significant. We would appeal directly to the person or persons in that car to please search their hearts and tell what they know."
McCartney (33) was stabbed to death outside a Belfast pub after a fight. The victim's sisters and fiancée, who claimed the murderers were being protected by a wall of silence by the Republican Movement, have since taken their campaign for justice to the White House and European parliament.
Even though one man has been charged with the murder, they claim up to 15 people were involved in the attack close to Magennis's bar on January 31st last year.
The IRA later said it had expelled three of its men over the attack, and offered to shoot those responsible.
Sinn Fein also suspended 12 members and urged witnesses in the pub that night to tell authorities what they saw.