Scrub fire in Marlborough called suspicious

A scrub fire that broke out in Marlborough's Wairau Valley is being treated as suspicious, firefighters say.

Fire and Emergency crews were called to an area about 40 metres off State Highway 63 halfway between Blenheim and Lake Rotoiti at 3.15pm this afternoon.

A spokesman said the fire spread across two hectares in light winds but did not threaten any properties and was extinguished by 6.45pm.

Crews from Wairau Valley, Waihopai and Blenheim stations were at the scene.

Fire investigators were yet to determine the exact cause of the fire, the spokesman said.