Fire crews have deployed heavy machinery in their fight against a timber and waste fire in Auckland's Onehunga

The fire has been contained in the Green Gorilla depot --it started just after 1pm yesterday afternoon.

Incident controller Brad Harvey says diggers and front end loaders are working to de-layer the fire, with crews watering the area to keep it damp.

He says it's under control, but they're expecting to continue through the night with a smaller crew.

Investigations into the fire's cause are ongoing.