The man died at in the early hours of this morning.
The man has been named locally as Michael Lynch, who is in his 60s, from Sliabh Sneacht, Buncrana.
A post mortem was carried out on Mr Lynch at Letterkenny General Hospital today but results of examination have not yet been released.
Gardai say details of how the man died or why he was arrested are not being released.
However a source has revealed they do not believe the death is suspicious.
A Garda forensics team spent most of today at Buncrana Garda station.
A full investigation was launched by the Garda Siochana Ombudsman Commission but it is unclear if this will continue.Tags: