The Pike River Recovery Agency's concept plan outlining three re-entry options has been signed off by Andrew Little, the Minister Responsible for Pike River Re-entry.

The Pike River Recovery Agency, Te Kāhui Whakamana Rua Tekau mā Iwa, chief executive Dave Gawn said it was focused on developing a safe plan to re-enter the mine drift, to promote accountability for this tragedy, to give the Pike River families closure and to help prevent future mining tragedies.

"The expert advice we've received shows a safe manned re-entry and recovery of the mine drift is technically feasible and the risks of harm can be managed and minimised," he said.

The agency had produced three options for consideration which would now be developed further.

Those included:

• Building a new 2m by 2m tunnel, around 200m long, to the Pit Bottom in Stone area

• Drilling a large diameter borehole

• Re-entering the main drift as it is with no second means of egress (exit)

"We've started to develop a detailed plan, with full risk assessments, hazard management plans and costings, and aim to get that back to the Minister for further consideration by the end of October," he said.

A procurement process was well underway to find contractors who would be involved in detailed planning and risk analysis, as well as mine sealing and rehabilitation works at the completion of the project.