What began with a routine police call in downtown Vancouver has ended with a major firearms seizure, the bust of a drug lab and the arrest of a man police are calling a well known drug trafficker.

Inspector John McKay isn't saying what led police to the Howe Street address, last night.

But he says the case escalated as the emergency response team was called to execute a high risk 'takedown' of a suspect on the Cambie bridge.

McKay says a loaded shotgun, nine-millimetre pistol and a replica handgun were found after the man was arrested.

A methamphetamine lab has also been shut down.

The name of the suspect and possible charges are expected later today.