Pike River Mine re-entry: Team edge towards second seal 170 metres inside

A Pike River Mine recovery workers broke through the seal for the first time last month. Photo / FRG

The first section of the Pike River Mine drift to be explored during the highly anticipated re-entry has not found anything of interest, officials confirmed today.

Expert miners made the first foray into the West Coast mine last month to start an operation trying to recover the 29 men killed during the November 19, 2010, disaster.

The Pike River Recovery Agency (PRRA) had been working for months to purge methane and oxygen from the mine by pumping in nitrogen through pipes before they proceeded underground.

After some delays, a small team broke through the concrete seal of the mine on May 22 to cheers from family members who watched from outside.

It's been slow progress since then, with miners edging towards a seal lodged 170m inside the mine eight years ago.

Today, the PRRA confirmed that the forensic search of the first 30m-170m section of mine drift by the miners, with the support and oversight of the New Zealand Police, has found nothing of interest.

"This is an area that was traversed on a daily basis from when the New Zealand Mines Rescue built the 170m seal in 2011, until 2016 when the seal was shifted from 170m to 30m," chief operating officer Dinghy 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."

Police described the forensic search as a useful exercise in basic scene examination processes for the agency's underground teams.

"We have a good system running, involving briefings and debriefings," said Assistant Commissioner Tusha Penny.

"Police will remain on site in support of the agency throughout the recovery project, and will continue to adopt an agile approach in the event of a critical find, such as the discovery of human remains.

"This means that, in certain circumstances, police will consider deploying staff into the drift before it is fully recovered by the agency."

Significant dewatering infrastructure was installed in this area, to assist with the volumes of water running down the mine drift. It includes two weirs, gabion baskets, concrete blocks and "grizzlies" that filter heavier material from water.