The family of a County Tyrone nationalist councillor murdered in 1974 was lied to by the RUC police when they were told the killing had been re-investigated in 1993, it has emerged.
The admission was made in the Belfast High Court by a detective leading a new inquiry into the murder of Patsy Kelly during a meeting with a legal representative of the Kelly family.
Loyalist Ulster Freedom Fighters said they killed Mr Kelly, but it is believed that rogue members of the Ulster Defence Regiment may have been involved.
As Mr Kelly's relatives launched a legal bid to secure a fully independent investigation, Seamus Treacy QC, representing the Kelly family, told the court it was not enough for an English policeman seconded to the PSNI to be put in charge.
``This is a collusion case. Members of the UDR and RUC colluded in the killing of Mr Kelly and the subsequent cover-up,'' he said.
``The current investigation is being carried out by those who are part of the police force which is suspected by the applicant and by others as having colluded in the murder and subsequent cover-up of the murder of Mr Kelly.
``The investigation is for all practical purposes being conducted by police officers connected institutionally with those who are potentially under investigation.''
But it was the apparent falsification of a non-existent RUC inquiry 10 years ago which took the judge aback.
Detective Superintendent Andrew Hunter, who has headed the investigation since June 23, has said he could ``offer no explanation'' why Detective Inspector Green wrote to him on November 27 2001 to tell him that the case files had been ``misplaced'' following a 1993 re-examination of the murder by the RUC serious crime squad.
Mr Justice Brian Kerr said: ``If it's true that no reinvestigation took place in 1993 that does raise very considerable issues as to the claim by the respondents that they had put in place sufficient measures to ensure the independence of the investigation that is currently taking place.''
The judge adjourned the case for three weeks to allow both sides to prepare new papers in light of the allegations made in court.