The forensic examination of a stretch of the Pike River mine drift, or access tunnel, has not revealed anything of interest to the police criminal investigation, authorities said today.
In a complex and tricky operation, the recovery team is slowly making its way through the mine drift which was re-entered five weeks ago.
The forensic examination of the mine tunnel between 30 metres and 170 metres hasn't revealed anything of interest to the investigation.
1 NEWS' Lisa Davies reported from Greymouth that this is not a huge surprise given the foot traffic through that stretch of tunnel since the explosion in November 2010 which killed 29 men working in the mine.
Pike River Recovery Agency chief operating officer Dinghy Pattinson said it's an area that was traversed daily from when New Zealand Mines Rescue built the 170m seal in 2011, until 2016 when the seal was shifted from 170m to 30m.
Significant dewatering infrastructure was installed in this area to assist with the volumes of water running down the mine drift, Mr Pattinson said.
"Because of this, there were no expectations that items of interest would be found in this area, and New Zealand Police have confirmed this is the case," he said.
1 NEWS reporter Lisa Davies says the push is on to go beyond 170 metres.
"But it will still be months before they make the 1.8 kilometre trek to get to the electrical workings of the mine that could reveal finally the cause of the fatal blast," she said.