Police say a small plane that crashed shortly after takeoff in Papua New Guinea was overloaded with cocaine destined for the Australian market.
Police say the drug gang's "greed" played a role in its downfall.
The Cessna is believed to have transported more than 500 kg of cocaine worth A $ 80 million (US $ 57 million) when it fell on Monday.
Five men, all allegedly members of a Melbourne crime syndicate, were arrested.
In a statement, Australian police said the gang had been under surveillance for two years. The plane took off from Mareeba, in northern Queensland, on Sunday and flew at low altitude to avoid radar detection before landing at a remote airfield at Papa Lea Lea, north of Port Moresby.
Police say he was loaded with drugs for the flight back to Australia.
"AFP (Federal Police of Australia) claims that greed played a significant role in the union's activities and cannot rule out that the weight of cocaine has impacted the plane's take-off capability." police said in a statement.
The plane's wreckage was found abandoned and empty a short distance from the airport. The drugs, in 28 bags, along with an unspecified amount of Australian currency were later recovered by Australian and Papua New Guinea police.
The pilot – an Australian – surrendered to the Australian consulate in Papua New Guinea on Tuesday, police added. He was arrested and charged with an immigration crime.
Police said the five men were linked to Italian organized crime and were arrested in Queensland and Victoria shortly after the plane took off for Papua New Guinea. If convicted, they face life imprisonment.
"These arrests prove no matter how sophisticated or opportunistic attempts at organized crime are, or the methods they use, law enforcement is keeping pace and causing the most damage to these criminal endeavors," said AFP deputy commissioner Ian McCartney.