Two police officers have been disciplined internally in connection with the investigation into the murder of Portadown Catholic Robert Hamill, the Irish News has learned.
Last night the Police Ombudsman's office which is overseeing the inquiry into Mr Hamill's killing confirmed action had been taken against the pair.
"Two police officers have been the subject of disciplinary action following a PSNI investigation, supervised by the Police Ombudsman's office, of actions taken by the police in relation to the serious assault on Robert Hamill," said a spokesman.
A woman constable deployed at the scene in the aftermath of the attack on Mr Hamill on April 27, 1997 is believed to have been the subject of an internal probe over poor written records of the incident.
It is understood disciplinary action against the senior officer related to procedural issues involving the securing of the scene to preserve any forensic evidence.
However, the Irish News also understands that another two high-ranking officers are also part of the internal probe over their role in the murder investigation, although no disciplinary action can be taken against one who has now left the police service.
"There are several ongoing elements to the investigation in the Hamill case," was all a spokesman for the ombudsman's office would say.
The development comes as former RUC officer Robert Atkinson and two others are due to appear in court charged with conspiring to pervert the course of justice in relation to the circumstances surrounding the murder of Mr Hamill.
The charges relate to a telephone call to the house of a suspect hours after the 25-year-old was attacked by a 30-strong loyalist mob just yards from an RUC Land Rover after a night out in Portadown.
Mr Hamill, whose fiancee was expecting their third child at the time, never regained consciousness and died 12 days later in Belfast's Royal Victoria Hospital.
Police have denied claims that RUC officers on duty that night failed to intervene.
In the autumn, Canadian Judge Peter Cory is due to deliver his findings on six controversial killings, including that of Mr Hamill, with a view to determining whether there should be a public inquiry.