Underground mine experts are debating which is the better way of two methods of re-entering New Zealand's Pike River Coal mine to retrieve the bodies of the 29 men buried inside.

Experts hired by Pike River mine families met with the mine's new owner Solid Energy, Mines Rescue and government officials in Christchurch earlier today to discuss options for recovering bodies.

The men - including two Australians - have been entombed in the West Coast mine since a series of explosions tore through the mine in November, 2010.

A statement on behalf of the Pike River drift exploration working group, following the meeting, described it as constructive.

"Progress is being made, but there is more work to do."

The group is considering two methods for re-entering the drift - the main shaft that goes into the mine. One involves a staged re-entry and the other boring a shaft down to the drift.

The group believed that both have the potential to be done safely, but more work is needed before a decision is made on which is preferable.