An Australian robot is being flown to New Zealand after the mayor of the town at the centre of the mine rescue drama appealed for help to find out if 29 missing men are still alive.

The miners, including two Australians, are still trapped underground in the Pike River coal mine, five days after a massive explosion ripped through its underground tunnels.

Rescue hopes suffered a setback this morning when a robot sent into the mine to assess the conditions short-circuited and broke down after running into a puddle.

Today the Western Australian government confirmed it was sending a new robot to take part in the search of the mine, where conditions are too dangerous for human rescuers.

An Air New Zealand plane is on its way to WA to collect the robot, which is owned by the Water Corporation.

The Australian robot is a skid-steered remotely-operated vehicle equipped with cameras, lights, communications and gas testing equipment.

It is controlled via a fibre optic cable and has a range of up to six kilometres.

The mayor of the community at the centre of the mine rescue drama says the robot is the only thing that can tell desperate relatives whether their loved ones are alive or dead.

"I'm appealing to Prime Minister Gillard ... if you can get it on an Air Force plane and get it out to us, we would really appreciate it," Grey District mayor Tony Kokshoorn told the ABC's Dominique Schwartz.

"The eyes of that robot are the only eyes allowed down there at the moment.

"It would tell us if they're dead or alive - it's that simple."

Mr Kokshoorn said relatives had reacted with "enormous emotion and anger" when they were told of the first robot's failure.

"After five days our people are losing hope," he said.

"We need to know if we can get our men back."

This morning, authorities released photos of the missing men, including Australians William Joynson, 49, and Joshua Ufer, 25, both from Queensland.

But police Superintendent Gary Knowles said: "This is a very serious situation and the longer it goes on, hopes fade. We have to be realistic."

Supt Knowles said drilling of a bore hole to reach the mine shaft continued overnight.

Pike River CEO Peter Whittall said the bore hole was at 142 metres this morning.

He said crews had to stop and change drill bits overnight after running into very hard rock.

Drilling has since recommenced, but progress is slow.

If the final stage of drilling is successful, it is hoped a camera and laser-imaging equipment can be sent underground.

The bore will also be used to test air quality. Authorities say results so far on the presence of toxic gases show the environment is too hazardous to send rescuers underground.

The head of NZ Mines Rescue, Trevor Watts, said crews were enduring "heart-wrenching" frustration at not being able to deploy underground.

"The conditions that our rescue personnel are going to face are potentially going to be hostile," he said.