Relatives of those who died watch the operation, which could shed light on what happened during 2010 New Zealand disaster

This article is more than 9 months old

This article is more than 9 months old

A recovery team has broken through the 170-metre mark of the sealed-off Pike river mine and proceeded 20 metres along the unexplored drift to gather forensic evidence and search for the bodies of 29 men who died there after two explosions in 2010.

Sonya Rockhouse, whose son Ben died and other son Daniel survived, was outside the mine on Tuesday and said the process of re-entering seemed quick compared with the years of waiting and anguish the families had endured while lobbying multiple governments to bring their men home.

“I watched them walk through the doors and it was wonderful,” said Rockhouse, speaking from Greymouth on the west coast of New Zealand’s South Island.

“It’s what we’ve been fighting for for such a long time and it’s finally here, we just feel vindicated. People have been saying it can’t be done and here we are – we’ve done it. It’s just fantastic, a wonderful Christmas present.”

The Pike River Recovery Agency (PRRA) first re-entered the mine in May, after minister Andrew Little said the operation needed to take place to find out what happened underground and provide closure for the families.

First images emerge from New Zealand's Pike river mine Read more

The NZ$36m (£18m) operation has been working to increase the ventilation to allow workers to venture deeper into the mine to where human remains and forensic evidence are thought to be.

Tuesday is a significant milestone as it is believed the bodies of the 29 men lay beyond the 170m seal, as well as important clues to what happened before and during the explosions.

Rockhouse said that after Christmas teams would re-enter the mine and progress in 20-metre increments collecting evidence – which she hoped would be used to mount a prosecution case. In the first 20 metres no evidence had been found, Rockhouse said.

“It’s going to be a little bit of a slow process but as I said to Dinghy [Pattinson, who is leading recovery efforts] today, never mind we’ve waited nine years so just take your time and do it properly, that’s all we want,” said Rockhouse, whose son Daniel was also on site.

“We’ve always said it was safe and could be done, we just needed a government that believed that as well.”

“We want to get up to the end of the drift and see what can be seen. We just want to be able to put some closure on things, finally. And we want to get some prosecutions and have people held to account for what happened ... there needs to be some sort of justice.”

Weeks of testing has taken place to ensure the atmosphere is safe and stable in the 2.3-km drift.

“It’s now been two weeks since we started ventilating the drift. It has gone to plan and last week we confirmed fresh air was at borehole 53 at the top end of the drift,” Dinghy Pattinson, the chief operating officer of the PRRA, told local media.

Facebook Twitter Pinterest A view inside the mine during reopening on 21 May Photograph: Handout/Getty Images

“Over the past seven days we have been monitoring and assessing and have confirmed we have a stable atmosphere underground.”

Pattinson said Tuesday’s initial foray would help the team gather information to plan further missions next year.

“The two doors within the barrier will then be closed again until the new year when the entire barrier will be removed,” Pattinson said. “The information gathered during this brief re-entry will assist in planning the removal of the 170-metre barrier in January.”

Pike river mine disaster: operation to retrieve bodies called off at last minute Read more

Little, the minister in charge of the Pike River mine re-entry, said the recovery of bodies and evidence remained a priority for the Labour coalition government.

“We need to find out as much as possible about what caused 29 men to go to work and not come home. The safe recovery of the mine drift, and its forensic examination, is part of an overdue act of justice.”

Little said the country’s employment oversight body, WorkSafe, had made an exemption to one aspect of mining regulations to allow the exploration of the drift to get underway.

“The agency was required to demonstrate its plan was as safe or safer than the regulation.” Little said.