The headstone of the grave at Carnmoney Cemetery was completely destroyed in the attack.

Mr McColgan, 20, was shot dead as he arrived for work at a postal depot in the loyalist Rathcoole estate on the outskirts of north Belfast on 12 January.

Daniel McColgan: Catholic postal worker shot dead in north Belfast

The Ulster Defence Association said it carried out the killing which sparked a wave of revulsion in Northern Ireland.

However, so far no-one has been charged in connection with the murder.

A £20,000 reward is being offered for information leading to the prosecution of the loyalist killers.

Police took the unusual step of announcing details of the reward money, which has been provided by a number of groups.

The killing was followed by a threat in the name of the so-called Red Hand Defenders, a cover name used in the past by the UDA and the Loyalist Volunteer Force, against all Catholic postal workers and Catholic teachers.

The threats were subsequently withdrawn.

The UDA initially used the cover name when admitting it had murdered Mr McColgan.

But it later admitted the murder, and four days after the killing ordered the Red Hand Defenders - the name being used by an element in its own ranks - to stand down.