The extent of the investigation into the murder of Det. Garda Colm Horkan involves 200 statements and 250 exhibits, a court has been told.
The file into the murder also includes 70 CCTV exhibits and the content of ten electronic devices, while Gardai are also speaking to a person in Australia as part of their investigation.
Details of the investigation were outlined at Harristown District Court in Castlerea by Sgt Paddy McGirl, who said he was confident the book of evidence would be completed within two weeks.
Stephen Silver of Aughaward, Foxford, Co Mayo, is charged with the murder of Det. Garda Horkan in Castlerea on June 17, and was due to appear before the court by video link.
But defence solicitor Marina Moran of Gearoid Geraghty & Company said that the defendant was still receiving at the Central Mental Hospital.
It is the fifth time that the 43-year old has been deemed unfit to appear by video link at Harristown District Court in Roscommon.
Sgt McGirl told Judge Deirdre Gearty that the investigation is ongoing and also complete.
“The book of evidence is not yet ready. The investigation file is nearing completion,” he said.
“This is a substantive file. There have been 200 statements, 250 exhibits, 70 separate segments of CCTV footage, ten electronic devices downloaded.
“In addition, the Gardai are making enquiries with a witness in Australia as well, so there are a number of reports outstanding and we are expecting to be in receipt of those reports this week so I would expect that the file will be completed within two weeks,” he said.
His application for Silver to be remanded in custody to appear before Harristown District Court by video link on September 4 was granted by Judge Gearty.