A coroner has expressed frustration at the lack of progress in the case of a dissident republican who killed himself in police custody.
Real IRA man John Brady, 40, was found hanged at Strand Road police station in October 2009.
The case is shrouded in controversy over allegations that two officers from the Police Service of Northern Ireland's (PSNI) C3 unit - formerly known as Special Branch - visited the veteran republican on three separate occasions before his death.
Judge Brian Sherrard told a preliminary hearing at Belfast Coroner's Court: "It is a matter of regret that we have not managed to make more progress than we have done."
Rumours of C3 involvement have led to speculation 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.
The court also heard that some security documents related to the high-profile case are so sensitive, the coroner's legal representatives have not been allowed to see them.
Judge Sherrard revealed he met with police on Wednesday to look at the papers personally, adding: "As it turns out the counsel instructed does not have sufficient clearance."
Mr Brady was jailed during the Troubles for murdering a policeman and had been arrested in Strabane while on parole on suspicion of assault.
The court heard that a copy of CCTV footage from the custody suite at Strand Road station had not been received by the Brady family's legal team and that statements from C3 officers, provided to the Police Ombudsman, have also not been shared.
Tony McGleenan QC, representing the PSNI, said a DVD recording had been handed over to the Coroner Service for dissemination but the officer's statements required further analysis to ensure there were no breaches of State secrets.
The barrister accepted an appeal from the coroner that the matter be addressed urgently.
Meanwhile the coroner has also demanded to see all information relating to Mr Brady's arrest and the reason for it, notebooks from officers involved in his detention and transcripts from any question and answer sessions that may have taken place before his death.
He also wants any notes taken by the custody sergeant at Strand Road to be handed over for consideration.
"The community has an interest in the arrest and what brought Mr Brady into custody," said Judge Sherrard.
"It may well be that there is nothing here and that the various reasons for suspicion and concerns fall away but I am of the view that they may be potentially relevant."
Meanwhile it was confirmed that the inquest is to be heard without a jury in Londonderry or Strabane, subject to court availability.
Afterwards solicitor Aiden Carlin, representing the Brady family, said: "We are concerned at the delay but the family are greatly encouraged by the fact that the inquest is now going to be listed in Derry as soon as practicable."
The case has been adjourned for another review on May 5.