Five New Zealand Defence Force firefighters joined in the fight to help battle wildfires in Tasmania.

A photo released by the NZDF shows the kiwis posing for a group photo with their Australian colleagues after a hard day's work on the fireline at Wuthering Heights in the state's northwest.

NZDF firefighters are doing their bit to help their Australian colleagues. Photo: National Rural Fire Authority.

Air Commodore (AIRCDRE) Kevin McEvoy, Acting Commander Joint Forces New Zealand, says the NZDF firefighters were fighting the Wuthering Heights fire, which has burnt nearly 20,000 hectares of forest.

'Although this fire is largely under control, the weather forecast for the next few days could mean that some of the fires could flare up again.

'Our team is working on the perimeter, doing what is known as ‘cold tracking', which involves locating hotspots, digging them up using hand tools, and extinguishing them by calling in helicopters if necessary.”

The NZDF crew are staying in the Arthur River township on the west coast and are being flown by helicopter to locations each morning.

They will help firefighting crews in Tasmania until February 18.