Fire fighters have controlled a pine forest fire on McLeans Island, northwest of Christchurch.

Assistant Area Commander Craig Crawford says the fire was threatening powerlines and five pumping appliances, three tankers, three helicopters and up to seven private tankers were brought in to fight the blaze.

Around five hectares have been affected and Mr Crawford says a fire was deliberately lit in the same area yesterday.

Today's blaze is being treated as suspicious as well.