UPDATED 10.44am: A 40-year-old man allegedly behind three fires in Dunedin overnight has been arrested.

He's been charged with deliberately setting fire to a building near the Cadbury factory, a flat on Cargill Street, and the historic Allbell Chambers on Stuart Street.

The category 2 historic property was built in 1909, and recently housed shops, offices and the Di Lusso restaurant.

The man's due to appear in the Dunedin District Court later today.

Police say their investigations into the three arsons are ongoing.

Newstalk ZB understands the suspect was apprehended at the scene of one of the fires. 

The Allbell Chambers on Stuart St was engulfed by fire when the alarm was raised just after four this morning.

Five fire trucks, including a turntable ladder, were needed to fight the blaze which was well involved when firefighters arrived.

There are no reports of injuries or people inside the building.

Fire safety officers will be investigating the cause of the blaze this morning.