Two Hunter mine rescue experts have been rushed to New Zealand to join the efforts at Pike River coalmine, where hopes are dwindling for 29 workers missing following a massive gas blast.
Newcastle-based Mines Rescue state manager Seamus Devlin and David Connell, who manages the Hunter Valley mines rescue station at Singleton, have flown to New Zealand's South Island.
Tests show that a fire burning underground was generating toxic gases at the mine, 46 kilometres north-east of the west-coast town of Greymouth.
It is understood a request was specifically made for the two Hunter experts to join the rescue operation after Friday's explosion.
Mines Rescue Service general manager Paul Healey said the two men's experience had made them valuable to the New Zealand mine rescue operation.
"David and Seamus went over [to Christchurch] first up on Saturday morning," Mr Healey said.
"They've been invited in by the head of New Zealand mine rescue, Trevor Watts. They're well-suited and well-experienced for something like this.
"Seamus has mine rescue experience that goes back 20 years [and] David's been there for five years.
"He's had operational experience at a number of mines."
The pair have worked in various mine rescue operations, including Beaconsfield goldmine in Tasmania, where one miner died after an earthquake and two others, Brant Webb and Todd Russell, were found alive five days later and freed after a 10-day operation.
Mines Rescue has also sent over a back-up team of eight brigadesmen to relieve New Zealand rescuer workers if needed.
That team is based in Christchurch.
Family members of the missing miners visited the site yesterday as rescue attempts were put on hold because of the dangerous conditions within the mine.
Among the two Australian miners missing is 25-year-old driller Josh Ufer, who was working for Hunter drilling company Valley Longwall at the time of the accident.
The two mine workers have not been heard from since the explosion, which has also trapped 24 New Zealanders, two Britons and a South African.
The name of the other Australian worker trapped in the mine remains unconfirmed, but he is believed to have a wife and two children. with AAP