Emergency services were called to the scene of the former Sisters of Mercy Convent in the town on Tuesday afternoon after smoke was seen rising from the building.
Scenes of Crime officers examined the scene yesterday and are satisfied the extensive damage is as a result of criminal damage.
The convent has been out of use for the past 25 years and planning had been granted for a €10 million redevelopment of the site.
Speaking to RedFM News, West Cork Crime Prevention Officer Sgt James O'Donovan is appealing for any witnesses to come forward:
Anyone with any information is asked to contact Clonakilty Garda Station on 023 882 1570, the Garda Confidential Line on 1800 666 111 or any Garda Station.
