A long-awaited inquest for missing teenager Arlene Arkinson has been stalled because of ongoing issues over disclosure.
The case, which is already behind schedule, was expected to conclude this week but has been further delayed to facilitate searches for police documents.
The missing papers relate to the monitoring of child killer Robert Howard after his release from police custody in 1994, as well as a 2002 review of police actions.
Fifteen-year-old Arlene, from Castlederg in Co Tyrone, vanished after a night out across the border in August 1994. Her body has never been found.
She was last seen with Howard, who was acquitted of her murder in 2005 by a jury unaware of his conviction for killing a teenager in south London several years earlier.
Howard (71), who was always the prime suspect in the Arkinson case, died in prison last year.
Last month former Chief Superintendent Eric Anderson told the inquest he had ordered covert 24/7 surveillance of Howard in the weeks after Arlene's disappearance, which was sanctioned by RUC headquarters.
As yet no paper trail has been found to substantiate the claim, the court heard.
Kevin Rooney QC, representing the PSNI, said: "There are no documents at this point in time.
"I believe it is unlikely we will find any documents given the passage of time but he (Mr Anderson) himself will give evidence."
Mr Anderson, who is battling ill health and gave evidence via Skype, has struggled to recall exactly who was involved in the operation, it was claimed.
Mr Rooney added: "Headquarters authorised the surveillance and one particular officer would telephone him and he met this officer on one or two occasions, but he just can't remember the name of that particular officer."
There were heated exchanges when Henry Toner QC, lawyer for the Arkinson family, asked if there was an "institutional incapability" within the PSNI to locate the documentation.
Mr Rooney hit back: "They are in the 66 folders.
"It is getting tiresome to have Mr Toner, on every single occasion, criticise the police."
Further claims that former RUC Chief Constable Sir Hugh Annesley ordered a search at the home and garden of the missing teenager's sister Kathleen Arkinson must also be explored, the court was told.
Lawyers are expected to convene on Friday to discuss the way forward, but no evidence will be heard until April 18.
The hearing was adjourned.