SYDNEY (AP) — Australian authorities said Tuesday they had seized a large quantity of cocaine from a fishing boat in treacherous seas off the east coast.

A law enforcement team intercepted the Australian trawler Coralynne on Saturday night after New Zealand authorities tipped Australians about the boat being tracked in a stretch of ocean not usually visited by trawlers. Australian intelligence officers then saw the trawler meet a larger ship and transfer the drugs. Australian officials say the larger ship might have come from South America.

Officers boarded the Coralynne in 3.5-meter (11-foot) seas, arrested three crew members and towed the trawler to Sydney Harbor, officials said.

Three men — a 40 -year-old Hong Konger and Australians aged 32 and 27 — were refused bail in a Sydney court on Monday charged with attempting to import a commercial quantity of cocaine, a joint statement by the Australian Federal Police, Australian Border Force and New South Wales state Police said on Tuesday. Each faces a potential life prison sentence if convicted. None has entered a plea.

Australian Border Force State Commander Danielle Yannopoulos said the haul was probably Australia’s biggest cocaine seizure since 2017.

While the haul had yet to be weighed, Australian Federal Police Assistant Commissioner Justine Gough estimated it weighed up to 1 metric ton (1.1 U.S. ton) and would sell in Australia for up to 250 million Australia dollars ($180 million).

New South Wales Police State Crime Commander Assistant Commissioner Stuart Smith said the need to mitigate the spread of coronavirus added another layer of difficulty to the operation.

“A lot of this product comes from countries that are at risk, and are dealing with the risk of COVID-19,” Smith said.

The three arrested crew tested negative to the virus, Smith said.