Rescue teams are still not able to gain access into a New Zealand coal mine where 29 miners remain trapped for a fifth day, authorities say.
Toxic gas levels were still too dangerous to allow rescue teams to enter the Pike River coal mine where 29 miners remain trapped, Superintendent Gary Knowles told reporters in Greymouth on teh South Island.
"Whilst I can understand (the families') frustration, we are doing everything possible to go underground," Supt Knowles said.
"Obviously over time, hopes diminish." Drilling of a small vertical bore shaft broke through early on Wednesday it is hoped a camera and listening device can be lowered into the main access tunnel.
Miner's hat found
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A robot sent down into the mine captured footage of a miner's hat with the light still on, Supt Knowles said.
"It's pretty amazing that it was still working underground," he said. A second robot from New Zealand Defence is still in the tunnel and has half an hour of functioning time left. A third robot from Australia arrived on Wednesday morning and would be tested later today, Supt Knowles said.
Hopes diminishing
Pike River Mine chief executive Peter Whittall said officials had a "sobering" meeting with families this morning.
"There's obviously a very large understanding amongst the group that the gases we are finding from this borehole ... the length of time ... is making their hopes diminish and making it more difficult for them to hold out that hope that all 29 of those are waiting for us as we have hoped from day one," Mr Whittall, who appeared haggard and drawn, said.
"I certainly hope there waiting for us down there, I certainly hope I see them again."
Drill breaks through
After three days of drilling through rugged terrain and dense rock, crews finally broke through to the mine at 7am (0500 AEDT).
Officials had yet to determine whether a camera could be sent down the hole, Mr Whittall said.
"There is a reasonable flow of air, warm air," he said. Mr Whittall said footage from the first robot had not shown any sign of the miners.
"It doesn't show you anyone is there, it doesn't show you that anyone was there," he said. Reports four of the miners were in a safer area were not true, Supt Knowles stressed.
"A lot of comments you have made are not helpful and distressing for the families," Supt Knowles said during a heated exchange with reporters.
Gas in NZ mine high in methane
The gas that escaped from a bore hole drilled into the mine is high in carbon dioxide and methane and low in oxygen, Mr Whittall says.
This was expected but not the news that families of the trapped 29 miners, including two Australians, wanted to hear, he said.
The samples from the bore hole were now being tested, he said. It was still too dangerous for rescue teams to enter the mine, he said.
