Two sources, whose names have been suppressed over fears they would be "punished" or fired by Chevron, told Energy News on Monday that a worker at the Wheatstone platform had tested positive for COVID-19.
One source told Energy News the worker "is a vendor who spent two weeks in quarantine before coming out," but subsequently tested positive. This was corroborated by a reliable second source.
It is not clear whether the worker was symptomatic.
"All flights are cancelled until they find out whether anyone else is infectored or the tests are a false positive" the second source told Energy News on Monday.
Flights to Chevron's Wheatstone platform are chartered from CHC Helicopters.
Chevron Australia and the National Offshore Petroleum Safety and Environmental Management Authority both confirmed a positive test at Wheatstone, but urged caution stating that there was a clear chance it was a false-positive.
The WA Health Department could not be reached.
If confirmed, the COVID-19 case would be the first in Australia outside of hotel quarantine in more than three months.
The Wheatstone platform is located in Commonwealth waters about 250 kilometres offshore.