UPDATED 10.28am: Police are investigating a home invasion in which a man threatened residents with a gun and shot their dog on Auckland's North Shore early this morning.

It is understood that just after midnight a gun-wielding man entered a house on College Rd in Northcote.

He demanded money and when the residents did not have what he wanted he shot their dog four times.

He further threatened the residents with the gun.

The man then left the property.

The residents were not injured and the dog has been taken to a vet.

A Herald photographer at the scene says an armed officer is patrolling the perimeter of the property, which is cordoned off by police emergency tape.

Another officer, unarmed, is patrolling neighbouring homes.

Forensic detectives in white boiler suits are doing a scene examination at the weatherboard house. Three cars are parked in the driveway.

North Shore Area Commander, Inspector Shanan Gray, said they're hoping to get some solid information from the victims to find him as soon as possible.