Police lack evidence that a vulnerable man arrested during one of Australia's biggest ever drug busts knew he was handling cocaine, a judge has heard.
Kristian Faumui, 26, was granted bail in the NSW Supreme Court on Thursday after his lawyer successfully argued he was vulnerable in prison due to a significant brain injury.
The Liverpool man was arrested in June after he and another man were allegedly discovered at a property on Sydney's outskirts with 2.7 tonnes of cocaine.
Federal police raided the Londonderry property and allegedly located the drugs in plastic tubs underneath shipping containers.
The tubs were buried in underground bunkers concealed by false container floors, police said.
The estimated street value of the cocaine is $816 million, based on it being equivalent to roughly three million deals.
Faumui and Plumpton man Andrew Whata Fepuleai, 21, are charged with possessing a commercial quantity of the drug, a charge that carries a maximum sentence of life in prison.
But the case against Faumui was called into question by his barrister on Thursday.
James Moore told the court his client was vulnerable to exploitation after he was injured in a car accident when he was four, and did not know he was moving the illicit drugs.
"There are real evidentiary issues with the prosecution case," Mr Moore said.
"There is an absence of direct evidence (Faumui) knew what he was dealing with.
"It is routinely the case that those who are senior (in criminal enterprises) will engage vulnerable young persons ... without telling that person the ins and outs."
Faumui's only connection to the whole operation was being seen moving the bags, Mr Moore said.
The Crown opposed bail, citing Faumi as a flight risk.
"Where is he going to go? He's a 26-year-old man with very strong family support," Justice Richard Cavanagh said, as the man's parents sat in court.
"It's not immediately apparent (Faumui) is even capable of that - not without his parents, and they don't seem like the kind of people who would do that."
Faumui will remain under strict house arrest while on bail, with one of his parents required to be at home with him at all times.
The mammoth Sydney bust was the standout find for investigators under Operation Minjiang, a joint taskforce headquartered in Queensland.
Police allege the cocaine seized in Londonderry was imported near Midge Point, north of Mackay, and transported to NSW under the orders of a Sydney organised crime group.
Six other people have been charged with varying offences including possessing illicit drugs and dealing with proceeds of crime.
Faumui and Fepuleai will return to court on August 7.
