Two men have been charged in Sydney, including an alleged drug importation kingpin, and about 500 kilograms of cocaine seized in the Solomon Islands in an international probe.
A joint investigation involving Australian, Solomon Islands and US officials ended on Thursday when the half-tonne of drugs - a magnitude not seen before by the South Pacific nation, was discovered inside the hull of a Belgian-registered, 44-foot and double-masted yacht moored in Honiara.
The cache was concealed and stored inside a steering mechanism that flows through the Vieux Malin vessel.
The Australian Federal Police allege the large yacht travelled from South America across the Pacific Ocean, and the syndicate behind the cocaine haul was arranging another "handover" at sea before venturing to Sydney.
Simultaneous to Thursday's discovery, two Australian citizens were arrested over their alleged involvement in the planned importation and faced Sydney's Central Local Court on Friday.
Zhen Tao Qi, 41, from Wahroonga has been charged with knowingly dealing in money or other property which is an instrument of crime valued at greater than $50,000, and conspiracy to import commercial quantity of border-controlled drugs, which carries a maximum penalty of life behind bars.
AFP Detective Superintendent Ben McQuillan said they suspect Qi is a senior syndicate figure, if not the head.
"In relation to the large-scale importation of narcotics, this person has been looked at for quite some time," he told reporters in Sydney on Saturday.
Zheng Zhao, 39, from Bonnyrigg Heights is also facing one count of dealing with an instrument of crime, which AFP allege was "in relation to the transfer or handover of money in payment or furtherance of the importation".
Qi and Zhao were each refused bail, with their matters due back in court on November 28.
Search warrants were also carried out in Dolls Point and Caringbah with items and electronic material seized.
It is the largest major organised crime probe undertaken by AFP with the Royal Solomon Islands Police Force.
"We're still yet to completely weigh the seizure and to analyse it but I think I'd be comfortable in saying probably a street value of between $200 to $300 million would be a reasonable estimate," Det Sup McQuillan said.
"It's certainly a seizure which ... the magnitude has not been seen previously in that part of the world."
He said upwards of eight tonnes of cocaine has now been seized in similar circumstances with "an emerging methodology" since February 2016, "most of which, if not all of which, we believe was destined for Australia".
AFP are interested in speaking to the yacht's crew, who they understand are no longer in the Solomon Islands.
© AAP 2018