The former Belconnen Police Station has been set on fire just two months after police vacated the building.
ACT Fire and Rescue units were called to the Lathlain Street building at 1.15am yesterday after a fire was detected in the former criminal investigations office.
Between $10,000 and $15,000 damage was caused, mainly to the windows, roof and door of the office.
Forensics and criminal investigations teams have inspected the building and are now investigating how the fire started.
Police are appealing for any witnesses to the blaze to call crime stoppers on 1800 333 000.