Police asked to appear at an inquiry into the murder of a County Armagh man fear their lives are at risk if they are identified, a court has heard.
Robert Hamill was attacked by a loyalist mob in 1997
The claim was made by a barrister representing 20 ex-officers called as witnesses at the inquiry into the 1987 killing of Robert Hamill in Portadown.
The officers began a legal challenge after the inquiry ruled they could not give their evidence anonymously.
The High Court challenge has led to the inquiry being indefinitely postponed.
The officers have requested to be screened and known only by an initial while giving their evidence.
Their barrister said to deny his client's this level of anonymity was a breach of the European Convention of Human Rights.
Mr Hamill, a 25-year-old Catholic, died in hospital after being attacked by a loyalist mob in Portadown in 1997. No-one has been convicted over his death.
Police have denied eye witness claims that four RUC officers in a Land Rover saw what was happening and failed to intervene.
The inquiry into Mr Hamill's death, chaired by retired judge Sir Edwin Jowitt, was recommended by ex-judge Peter Cory, who was tasked to probe alleged collusion.
It was set up to determine if police committed any wrongful act or omission.
Speaking outside the court, solicitor Barra McGrory, who is representing the Hamill family, said he was "mystified" as to why the police would want anonymity as none had been given at the original murder trial.
He was referring to the Crown Court case in 1999 when a man was acquitted of the murder but convicted of affray and jailed for four years.
The inquiry had originally been scheduled to begin hearings in Belfast on 5 September.