Papua New Guinea's fuel distributor InterOil has denied that its fuel may have been contaminated, leading to last Thursday's fatal aircraft crash in Madang.
The contamination theory was put forward by a Lae businessman which the newspaper, The Australian, reported at the weekend.
But the PNG Accident Investigation Commission has told the newspaper, The National, that the contamination theory can be ruled out.
InterOil said in a media statement immediately after the crash that it initiated its standard operating procedure to quarantine relevant fuel sources.
Its chief executive said the bad fuel theory was ruled out because another 15 aircraft also refuelled at Nadzab airport outside Lae.
He says tests have been carried out and refuelling operations at Nadzab have recommenced.