A cargo ship carrying 16 crew members with suspected COVID-19 will arrive in Fremantle on Monday morning.
The bulk carrier, Ken Hou, was meant to dock in Albany on the weekend after arriving from Thailand.
It has now been instructed to head to Fremantle so the crew, who are experiencing respiratory problems and high temperatures, can be assessed.
Premier Mark McGowan said the crew will be offered medical attention if required.
“The Australian Maritime Safety Authority is keen for the ship to stay in Cockburn Sound for some period,” he said.
“We'll work that through as to what the right arrangements are, but I've sought every assurance this morning that every precaution is in place to protect the state in this circumstance.”
Another cargo ship, the Poavosa Wisdom, is also on the radar after arriving in WA from Indonesia.
Two crew members have reported experiencing cold-like symptoms but Mr McGowan said it is unlikely they have COVID-19.
“The expectation, or the suspicion is that it’s not COVID, let’s hope that’s true,” he said.
“But I just wanted to be totally transparent and inform people that there is another ship that we have to analyse.”

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