Half a tonne of cocaine to be smuggled into Australia could have been the cause of a light plane crash in Papua New Guinea.
The heavy cargo, worth an estimated $80 million on the streets, was seized by police in PNG after a failed take off.
The crash occurred on the same day five men were arrested for allegedly conspiring to import more than 500kg of cocaine into Australia, police said on Saturday.
The men are alleged members of a Melbourne-based criminal syndicate with links to Italian organised crime.
They were arrested in Queensland and Victoria after the Cessna aircraft left Mareeba Airport, in the sunshine state's far north, bound for PNG last Sunday.
Police allege the men travelled from Sydney and Melbourne to Atherton, southwest of Cairns, between July 19 and 25, before facilitating the flight to collect the drugs.
"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.
Later the same day the plane crashed while trying to take off from a remote airstrip at Papa Lea Lea, north of Port Moresby.
"The AFP alleges greed played a significant part in the syndicate's activities and cannot rule out that the weight of the cocaine had an impact on the plane's ability to take off," the statement said.
Two days after the crash the pilot, an Australian man, was arrested after going to the Australian consulate in PNG.
He has been charged with a PNG immigration offence.
The five men arrested in Australia have been charged with conspiring to import the cocaine from PNG into Australia. They include four from Victoria aged 31, 33 and 61, and a 36-year-old from Sydney.
Police allege one of the Melbourne men was expected to transport the drugs south using a truck.
All five men face a maximum penalty of life imprisonment if convicted.
Police released photos of what appear to be cut-out plasterboard sheets, presumably making a concealed area to transport the cocaine in the back of a truck.
The crashed aircraft is shown on its belly in scrubland, one engine still smoking and a wing destroyed by fire.
The cocaine was wrapped in black plastic in large cubes.
Police have also seized property and financial assets valued at about $3.5 million suspected to be under the control of a syndicate member.
These include three properties, shares, account funds and a vehicle.