The cottage where Denis Donaldson was found shot dead on April 4th, 2006.
The second of two men arrested by gardaí as part of the investigation into the murder of Denis Donaldson has been released without charge.
The man, aged in his 30s, was released from Letterkenny Garda station last night without charge. He had been arrested on Sunday.
Gardaí say a file will be prepared for the Director of Public Prosecutions.
Investigating gardaí are continuing to appeal to anyone with information in relation to this murder to contact them at the incident room at Letterkenny Garda station on 074 9167100, the Garda Confidential Line at 1800 666111 or any Garda station.