"The AFP alleges greed played a significant part in the syndicate's activities and can not rule out that the weight of the cocaine had an impact on the plane's ability to take off", the statement said.
Meanwhile in Australia, members of a Melbourne-based criminal syndicate, with alleged links to Italian organised crime, had been charged for conspiring to import the cocaine from PNG into Australia.
"The aircraft flew at about 3000 feet from Mareeba to PNG, in an effort to avoid radar detection", Australian Federal Police said in a statement.
The Australian pilot of the Cessna 402C light aircraft had been arrested and charged with illegally entering the country.
Police had said he was helping with their inquiries and the 28 cartons of drugs were located after his arrest.
All five men face a maximum penalty of life imprisonment if convicted.
PNG authorities found the crashed Australian plane late last month but found no pilot or any cargo in sight.
Media in Papua New Guinea reported, citing the police, that it was largest drugs haul by value in PNG history. The drugs are still being analysed and a number of men are speaking with local authorities.
These include three properties, shares, account funds and a vehicle.
A 31-year-old man from Maribyrnong, in Melbourne, faced Cairns Magistrates Court on 27 July charged with offences including importing commercial quantities of border controlled drugs and laundering over $1million.
Two other men, aged 33 and 61, faced Melbourne Magistrates Court on the same day charged with conspiring to import commercial quantities border controlled drugs.
AFP Deputy Commissioner Investigations Ian McCartney said it's the end of a two-year multi-agency drugs operation.
"Those persons are encouraged to come forward to police, as we will find them", Manning warned.
'Australian law enforcement remains committed to working collectively to protect Australia, which is especially important now, due to the ongoing impact of the pandemic on the community'.