Almost a tonne of drugs has been discovered on a Marshall Islands-flag bulker in Australia.

The 900kg of cocaine was found on the 58,000-dwt supramax St Pinot (built 2018) at Kwinana Bulk Terminal in Western Australia (WA), the Daily Mail reported.

The haul, with a street value of at least $375m, is one of the country’s biggest ever.

The operation was a joint investigation by the Australian Federal Police (AFP), Australian Border Force and WA Police.

The cocaine is believed to have come from South America.

Video footage showed officers being lowered inside the hull of the St Pinot.

“The AFP, Australian Border Force and WA Police Force are searching a cargo vessel as part of an ongoing operation,” an AFP spokesperson told the Daily Mail on Wednesday.

The St Pinot had left the port of San Lorenzo in Argentina on 16 April before two other calls in the same country.

The ship had then sailed for five weeks to reach Fremantle in Australia, before heading to Kwinana.

There were no reports of any arrests made following the seizure.

AIS data showed the vessel still moored at the port on Thursday.

The vessel is owned by Shamrock Maritime of Monaco, which has been contacted for further information.

This is the third major cocaine seizure made in the state in recent months.

In March, police foiled a bid by a Mexican cartel to ship in 2.4 tonnes worth $1bn.

And a shipment was intercepted by US authorities off the coast of South America in November last year.