An Australian mine safety expert and a former senior New Zealand public servant have been named as Royal Commissioners in the Pike River mine tragedy inquiry.
The inquiry will examine the cause of the explosion, the subsequent deaths of 29 men, rescue operations and safety regulations.
Justice Graham Panckhurst, a Christchurch-based High Court judge, was last month selected to lead the inquiry.
Prime Minister John Key today announced Queensland commissioner for mine safety and health Stewart Bell and former Electoral Commission chief executive David Henry as the other two commissioners.
Mr Key said he had met Mr Bell in Wellington last week.
"He has over 25 years of experience in the mine sector and his strong background in safety is directly relevant to this royal commission."
Mr Key said Mr Henry, who was Inland Revenue chief executive from 1988 to 1995, brought years of experience as well as an inquiring mind to the commission.
The Governor-General would officially appoint the men later today and would sign off the final terms of reference for the inquiry.
"The final part of the terms of reference make it clear that the royal commission can inquire into any other matters that they deem to be appropriate, so they're wide-ranging."
Mr Key acknowledged the Queensland government for its co-operation in Mr Stewart's appointment.
"I spoke with Premier Anna Bligh over the weekend and she was keen to accommodate the royal commission," he said.
"Clearly there are benefits for mining in both countries and that will come from finding out what happened at Pike River."
Mr Key said the report back date for the inquiry would be no later than March 31, 2012.