A statement from the chief justice said the allegations were "that the prime minister failed to comply with administrative and financial processes including the normal borrowing process" for the loan.

"It is further alleged that the purchasing of the shares was in the interests of Oil Search Limited and not in the interests of the independent state of Papua New Guinea," Sir Salamo Injia said.

Mr O'Neill welcomed the announcement of a leadership tribunal, saying he was keen to clear his name.

"It is best that this tribunal is convened sooner rather than later," he said.

"The referral by the Ombudsman Commission is not on a decision on a personal matter, it relates to a government decision by the cabinet of which I am chairman."

Mr O'Neill also claimed there had been a large amount of "politically motivated misinformation" as well as "blatant lies" relating to the purchase of the Oil Search shares by the PNG government.

"The purchase of these shares is an investment in the key resource infrastructure of our country," he said.

"Without such investment we continue to be bystanders in our own resources sector, which has been the case in decades past."

Mr O'Neill has strong support in the coalition government and is protected from PNG's notoriously common no-confidence motions until February, when a constitutional grace period expires.