Rescuers plan to send a robot into the coal mine in New Zealand where 29 miners remain trapped once gas levels have dropped, a local newspaper reported on Monday.
The New Zealand herald reported that gas samples being taken at the Pike river colliery's main ventilation shaft were still showing high levels of carbon dioxide and methane on Monday, hampering the rescue effort.
Police commander Gary Knowles, who is overlooking the rescue operation, said that testing of gas levels in the mine was being carried out every half hour.
"The rescue team are still on standby, they are currently planning to go into the tunnel if the opportunity arises, they are currently looking at which sections they will enter first," he said.
There has been no contact with the miners since an explosion ripped through the underground mine on the country's west coast on Friday.