Fire has extensively damaged a large building in Nelson housing vehicle testing businesses.
The Fire Service said five fire trucks were sent to the scene after the alert was raised about 1.30am on Saturday and it took about 90 minutes to bring the blaze under control.
The building houses Vehicle Testing New Zealand and another automotive testing business.
Andrew Norris of Fire Southern Communications said the fire was contained in one half of the building, thanks to an effective fire wall. Crews worked to ensure the blaze did not endanger a large New World supermarket at the rear of the building.
The fire is being treated as suspicious and both police and fire safety officers will be investigating.