Papua New Guinea's Post-Courier newspaper has handed documents to the Ombudsman Commission which detail two bank accounts allegedly held in Singapore by two government ministers.
Last month, the paper alleged that the accounts contain 40 million US dollars gained from an illegal levy on every log exported from PNG.
The documents have also been given to a special police unit investigating money laundering.
The Post Courier's editor, Blaise Nangoi, says the move is unprecedented.
He says there had been immense pressure put on the newspaper to prove the veracity of the report.
Mr Nangoi says politicians and commentators have suggested it's a hoax or a beat up, and part of a supposed plot by the newspaper to discredit the country's leaders.
He says they stand by the story and believe it shows an illegal arrangement that needed to be exposed to allow the proper authorities to investigate.