Christchurch police are investigating a suspicious fire at a gang pad in Woodend.

Police received reports yesterday afternoon about a property on fire on Beach Road.

It turned out to be the Highway 61 gang headquarters.

Detective Sergeant Rex Barnett says shortly before the fire a station wagon had been seen arriving at the property, "and about five minutes later, a passer-by noticed some smoke coming from the building, then the fire brigade arrived."

Barnett says they're wanting to speak to anyone with information.