Two former Northern Ireland detectives were arrested today by Police Ombudsman investigators examining the RUC's handling of an inquiry into the murder of a man beaten to death by loyalist paramilitaries near Belfast.
They were detained for questioning about an alleged attempt to pervert the course of justice and misconduct in public office.
Ombudsman Nuala O'Loan, who is carrying out a major investigation into the case.
Both officers were involved in the investigation into the murder of Raymond McCord Jnr, who was beaten to death near Belfast in 1997 by members of the Ulster Volunteer Force (UVF).
It has been claimed that at least one of those responsible for the brutal killing was working for police Special Branch at the time.
Ombudsman Nuala O'Loan is carrying out a major investigation into the case.
A file has been submitted to the Public Prosecution Service and a report is expected to be published next month. Two premises were also searched as part of today's arrest operation.
Mrs O'Loan's report of her inquiry into the police investigation is expected to be one of the most damning published, with devastating claims that loyalist paramilitaries working as informers for police in Northern Ireland at that time were involved in a series of killings, but were never charged.
Mr McCord (22) was beaten to death by the UVF in Newtownabbey in November 1997 after falling out with former associates.
The two former detectives arrested today were detained for questioning at separate police stations, the Ombudsman Office said.