A robot sent into the Pike River mine was not waterproofed and malfunctioned when water fell onto it, relatives of the 29 miners trapped underground were told this morning.

A relative told the Herald after rescue authorities' 8am briefing that families had been told the Defence Force robot was in the mine but had broken down.

Relatives reacted angrily when told the robot had stopped working when it was exposed to water.

Tasman Area Police Commander Superintendent Gary Knowles told a media conference the robot was sent into the mine at 6am and he was informed at 8am it had broken down.

Reporters were told the robot had only got 550m into the mine when it malfunctioned.

"We will be speaking to the Defence Force this morning to establish whether it [the robot] got any visuals. Anything of a visual nature would only show us a clear tunnel because there was no men in that area."

Mr Knowles said rescuers were trying to get more advanced robots from Western Australia and America to deploy underground.

He said authorities were "pulling all strings" and the Royal New Zealand Air Force would fly in the Australian robot on a Hercules aircraft.

Pike River chairman John Dow said he understood water had affected the robot.

"I understand the water in the tunnel hit the robot as it was going in."

'Kick in the guts'

Grey District Mayor Tony Kokshoorn said the breakdown of the robot had angered family members and made them question the rescue efforts at Pike River.

Hearing the high-tech defence force robot had short circuited after water from the ceiling dripped on it was a "kick in the guts" for them, he said.

"We were hanging our hopes on the robot because it can get around anywhere in the mine and tell you where our miners are and how they are. Without rescuers it was the next best thing.

"We walked in there and it was a kick in the guts. It's history. Imagine how that went down."

"People really started to be questioning of the procedures. There's a certain amount of anger coming up now. It was very emotional for everyone including myself."

Frustration turned to anger when family members after they were told a replacement robot was being flown in from the United States, he said.

"They asked why didn't they have a backup on their way already. Hell, it's desperate. It's so frustrating."

He implored families and the wider community not to give up hope of getting the miners out alive.

News of 29 Chinese miners rescued from a coal mine yesterday had buoyed some spirits, he says.

"We've got to take heart from those kinds of things."

Mr Knowles told a media conference last night that Defence Force staff had been practising with the robot all day, testing it on the road to make sure it could handle the terrain inside the mine and go the distance.

He said the robot, also used to detect and dispose of bombs, would have a rag attached to its arm to ascertain if any air was moving in the tunnel. It would have to drag its own fibre-optic cables behind it as it moved into the mine.

The trapped miners:
Conrad Adams, 43 (Greymouth), Malcolm Campbell, 25 (Greymouth - Scottish), Glen Cruse, 35 (Cobden), Allan Dixon, 59 (Runanga), Zen Drew, 21 (Greymouth), Christopher Duggan, 31 (Greymouth), Joseph Dunbar, 17 (Greymouth), John Hale, 45 (Ruatapu), Daniel Herk, 36 (Runanga), David Hoggart, 33 (Foxton), Richard Holling, 41 (Blackball), Andrew Hurren, 32 (Greymouth), Jacobus 'Koos' Jonker, 47 (Coben - South African), William Joynson, 49 (Dunollie - Australian), Riki Keane, 28 (Greymouth), Terry Kitchin, 41 (Runanga), Samuel Mackie, 26 (Greymouth), Francis Marden, 42 (Runanga), Michael Monk, 23 (Greymouth), Stuart Mudge, 31 (Runanga), Kane Nieper, 33 (Greymouth), Peter O'Neill, 55 (Runanga), Milton Osborne, 54 (Ngahere), Brendon Palmer, 27 (Cobden), Benjamin Rockhouse, 21 (Greymouth), Peter Rodger, 40 (Greymouth - British), Blair Sims, 28 (Greymouth), Joshua Ufer 25 (Australia), Keith Valli, 62 (Winton).