THE livestock carrier Diamantina arrived at Darwin’s East Arm Wharf on 27 December after a journey from Indonesia.

On 28 December, a 25-year-old crew member onboard the vessel tested positive to coronavirus. Later, a 35-year-old crew member also returned what authorities have called a “low positive” test result. The two are receiving treatment at Royal Darwin Hospital.

“The advice we’ve had is that may be a residual case, so somebody who’s previously had COVID-19 still coming up with a low positive case,” Acting Chief Minister Nicole Manison said.

“Out of precaution, they’ve been taken to Royal Darwin Hospital in isolation, where they are being treated and monitored.”

Twenty-eight people were onboard the ship when it docked and about a dozen of those are in supervised quarantine in Howard Springs.

A number of Darwin Port staff were directed to self-isolate after coming into contact with the Diamantina crew, but none have since returned positive coronavirus tests.

NT health authorities say none of the crew left the vessel before the positive diagnosis, and there were strict protocols in place for any ships arriving into the Northern Territory.

The Diamantina is flagged in Singapore but is owned by an Australian company based in the NT.

The incident brought renewed calls from the Maritime Union of Australia for a “cohesive and nationally-consistent policy on addressing COVID risks involving international shipping”.

MUA national secretary Paddy Crumlin said, “Vessels continued to dock around Australia inside the 14-day quarantine period imposed on other travellers, while the maritime arrival system remains reliant on a self-declaration system where a ship’s master is responsible for reporting if there are sick crew members onboard”.

MUA NT acting branch secretary and national Indigenous officer Thomas Mayor said, “The current system, which is reliant on international shipowners, driven by profit, self-reporting potential illnesses — knowing that this will cause them costly delays — cannot guarantee the safety of our members or the broader community”.

 “Thankfully, in this case the additional quarantine steps put in place by the Territory Government, which were developed in consultation with workers and the union, were effective at identifying the confirmed COVID case,” he said.

Darwin Port has been approached for comment.