Concerns are held for up to six Fremantle Port workers who boarded a live export ship before an outbreak of COVID-19 on the vessel was confirmed.
It comes amid growing tension over whether state or federal authorities were responsible for workers boarding the Al Kuwait, en route from the United Arab Emirates, after news emerged some of the crew had been unwell.
WA Police Commissioner Chris Dawson says a report from the vessel was submitted to the federal Department of Agriculture advising some of the crew had fevers on Wednesday.
The ship arrived in WA two days later. Six of the 48 multinational crew have since tested positive to the virus.
Premier Mark McGowan is angry the federal Department of Agriculture allowed the Al Kuwait to berth, given the ship had lodged a pre-arrival report saying three crew members were sick.
He said it was lucky no one got off the ship but it was unfortunate others had boarded the vessel.
Federal Agriculture Minister David Littleproud said the situation was handled correctly.
"I have asked my department to go back and double check and triple check to make sure that every protocol has been adhered to," Mr Littleproud said.
No crew members were permitted to disembark and all federal department staff who attended the vessel wore full personal protective equipment.
"The Human Biosecurity Officer was also not notified there was any issue of concern," the state government said in a statement.
Mr McGowan said he was concerned for the local workers and their families.
"We would have hoped that more red flags were raised that there were people who were sick on board so we could have been prepared," he said on Tuesday.
Mr McGowan said he didn't think information was deliberately withheld "but we certainly need to review the protocols".
"We're very concerned and to a degree, disappointed," he said.
The port workers are being isolated and contact tracing is under way while the six crew who tested positive are being quarantined at a Perth hotel.
The remaining 42 are well and remain on board the vessel.
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