CCTV footage will be central to an inquest into the death of a dissident republican who hanged himself in police custody, a coroner's court has heard.
Real IRA man John Brady, 40, was arrested in October 2009 and taken to Strand Road police station in Londonderry and was later found dead in his cell.
Hours of security camera footage must be considered ahead of an inquest which is due to be held in Omagh in May and is expected to last at least two weeks, a lawyer told coroner Joe McCrisken.
Brady family barrister Mark Mulholland QC said: "The core of the factual issues will feature the CCTV footage.
"Two intelligence officers attempted to get access to Mr Brady but were turned away by custody staff, which is why next of kin want to satisfy themselves."
The case is shrouded in controversy over allegations that two officers from the PSNI's C3 unit, formerly known as Special Branch, visited the veteran republican on three separate occasions before his death.
Rumours of C3 involvement have led to speculation that Mr Brady may have been subjected to a bid to turn him into an informer before he hanged himself in a consultation room.
But the Police Ombudsman subsequently examined these claims and found no evidence to support them.
The ombudsman said two intelligence officers did attempt to gain access to Mr Brady but were turned away by custody staff - a finding investigators said was substantiated by CCTV footage.