Police believe a fugitive on the run for over a month this morning broke into a farmhouse and stole a car, again evading their roadblocks.

Detective Senior Sergeant John Rae said a purple Ford Falcon with the numberplate CEF988 was stolen from a farm in the Tai Tapu area.

"I believe the car has been stolen by William Stewart, the man we have been looking for now for some weeks," Mr Rae said "And it could be anywhere in Canterbury by now".

The car had a full tank of petrol and a range of about 600km.

Mr Rae said Stewart, 47, had managed to avoid police road blocks in the area.

Police have been hunting for Stewart since February 10 when he disappeared near the Rangitata River during a police chase.

Police attribute a number of recent burglaries to him, with cold tablets and prescriptions taken from a Leeston pharmacy and codeine-based products at Tekapo and Fairlie.

He is thought to be stealing and discarding vehicles, with the tally now at three cars, a motorbike and a four-wheel-drive.

There are five warrants for Stewart's arrest and police have described him as "unpredictable" saying any sightings of him should be reported to police, but he should not be approached.

Stewart has previously frequented the area between Christchurch and Darfield and back to Temuka and Lake Tekapo.

Officers, including members of the armed offenders squad (AOS), yesterday cordoned off an area in Taitapu, 16km southwest of Christchurch near the Port Hills, believing Stewart was there.

Police evacuated nearby residents while they searched.

However, he did "a runner" again, and the cordon had been stood down, Sergeant Barry Hansen of Police communications told NZPA this morning.

Officers, the AOS and a helicopter unsuccessfully searched bush in Governors Bay on Friday following the sighting of a lone motorcyclist thought to be Stewart.

The man had bolted after reaching a police road block on Banks Peninsula, 21km southeast of Christchurch, about 4.30am.

Stewart is described as a Caucasian male, 177cm tall, of thin build. He has cut his long straggly hair down to a rough No 2 cut.

- NZPA and NZHERALD STAFF