Days after a Catholic man was murdered by a sectarian mob the police had evidence that a fellow officer protected one of the killers from prosecution, a public inquiry heard today.

Robert Hamill, 25, was beaten to death by a loyalist gang in Portadown, Co Armagh, on April 27, 1997, during a night out with friends, but no one has been convicted for the murder and police face claims that officers at the scene failed to protect Mr Hamill and later frustrated the investigation.

The opening session of the inquiry today heard that within two weeks of the killing police had names for those involved in the murder, plus evidence that a Royal Ulster Constabulary (RUC) reserve constable Robert Atkinson warned one of the killers to dispose of clothes worn in the attack and updated him on the investigation.

The Inquiry's lead counsel Ashley Underwood QC today outlined the details of the case, as members of the murdered man's family listened to proceedings in Belfast's Interpoint Centre.

Mr Underwood recounted how Mr Hamill was attacked while an RUC Land Rover with four armed officers was parked nearby, but the father-of-three suffered serious head injuries and died 11 days later in hospital.

But he added: "By May 10, 1997, the RUC had the identities of a number of Protestants who were said to have murdered Mr Hamill.

"Further, it had evidence that one of the reserve constables in the Land Rover, Mr Atkinson, had protected one of them, by telling him to get rid of his clothing and by keeping him updated about the investigation.

"However no one has been convicted of murdering Mr Hamill and only one person was convicted of affray arising out of the attack on him.

"Reserve constable Atkinson was eventually charged in relation to a conspiracy arising out of the alleged tip-offs that he gave, but was not prosecuted."