More than a week since flames ripped through Victoria's former Plaza Hotel building, police are calling the fire suspicious.

Police and fire investigators began their search of the rubble Monday in an attempt to determine the cause of the May 6 blaze that levelled the four-storey building at the corner of Government Street and Pandora Avenue.

"Our investigators, along with the Victoria Fire Department’s investigators, were on the site yesterday, and will be there for up to a few weeks," Victoria police said Tuesday.

"These type of investigations are lengthy and an appropriate amount of resources will be dedicated to investigate the origin of the fire." 

Firefighters were called to the Plaza Hotel on Government Street just before 5:30 a.m. and arrived to a fully involved fire. Officials said alarms at neighbouring properties went off, but not inside the vacant hotel.

The building's caretaker, Mike Draeger, has still not been located. 

The search for what caused the powerful inferno was put on hold as firefighters fought the flames for four days.