Six crew members of a live export ship docked in Fremantle have tested positive for COVID-19.
Premier Mark McGowan announced that Al Kuwait arrived in Fremantle last Friday having travelled from the United Arab Emirates.
"The Al Kuwait departed the United Arab Emirates on May 7 with a total of 48 crew members onboard," he said.
"This morning, seven crew members were tested for COVID-19.
"Six have tested positive, all males, and are being moved off the ship to a Perth hotel for quarantine purposes."
The premier expected more of the crew members to be diagnosed with COVID-19 over the following days.
A WA Health team is on board the ship to further assess the crew and provide advice around health and infection control going forward.
Mr McGowan said he had been advised the federal Department of Agriculture was told crew members had a fever but didn't pass that information on to Fremantle Port Authority before the vessel berthed.
"I don't want to point fingers at this point in time," Mr McGowan said on Tuesday.
"We're just trying to find out exactly what has gone on.
Mr McGowan said the state government wanted the ship to sail as soon as possible, but obviously needed to ensure the vessel was cleaned first.
"This is a fast-evolving situation today involving WA Health, West Australian Police, the Department of Primary Industries and Regional Development, the Fremantle Port, as well as the Australian Border Force and the Australian Maritime Safety Authority," he said.
"We're working with the ship's agents to get the ship to sail as soon as possible."
This news comes following a family of four testing positive for COVID-19 in WA yesterday.