Up to 16,000 pages of evidence are being examined as part of an investigation into the death of a man whose body was found in Newry Canal, a coroner heard.
Gareth O'Connor (24), who had been charged in the Republic with being a member of the Real IRA, vanished while en route to Dundalk Garda station in 2003.
A preliminary hearing of the inquest into the Co Armagh man's fate was held yesterday in Belfast.
Family solicitor Paul Dougan said: "The document page count is colossal, maybe 15-16,000 pages of material has been printed out, a lot of it is not hugely relevant but it is a huge exercise to familiarise yourself with its contents and that process is ongoing."
Mr O'Connor's family believed he was abducted and killed by the Provisional IRA. It had been feared the father of two had been "disappeared" forever before a tip-off led police to a section of the Newry Canal off the Omeath Road.
Detectives recovered a submerged blue Volkswagen Golf, the car Mr O'Connor was last seen driving through the south Armagh border village of Newtownhamilton on May 11, 2003. Inside lay his badly decomposed body.