UPDATED 9.30AM: Firefighters are uncertain whether a fire aboard a container ship in Tauranga is out.

The fire in the hull of the Kokopo Chief, moored in Tauranga, was doused by the ship's CO2 suppression system after escalating temperatures set it off on Sunday morning.

Firefighters and ship management are in discussions about entering the hull on Sunday morning to check if the CO2 discharge was effective in putting the fire out.

Sixteen fire trucks from Tauranga, Mt Maunganui, Rotorua and Hamilton remain at the scene.

EARLIER:

A ship fire has broken out in the hull of the Kokopo Chief, moored in Tauranga, with high temperatures setting off an alarm on Sunday morning.

Seventy firefighters are attending the fire, which is not affecting two of the ship's holds.

The ship's CO2 suppression system has been activated.

It is understood the ship is carrying 650 tonnes of dressed timber.

Northern fire communications shift manager Jaron Phillips says the alarm was raised at 1am.

"There's a fire in the hold of the ship's hull ... we're just getting additional fire crews in from as far away at Rotorua.

"The plan is to start moving containers from the ship."

Fire Communications said at 2am that firefighters in breathing apparatus were working to enter an adjacent ship to investigate "heat transfer".

- Stuff