The WA Health Department has launched an investigation into how COVID-19 jumped between neighbouring rooms in hotel quarantine in Perth.
Genomic testing has shown two sets of couples on the sixth floor of the Mercure Hotel Perth had the same variant of the virus despite arriving from different countries at different times.
In a statement, the WA Health Department confirmed the two new cases, which had previously been reported as being overseas acquired.
"All other guests who previously stayed on the same (sixth) floor during this time and have been released from the hotel facility tested negative prior to release," the statement read.
"These guests will be re-tested and directed to self-isolate until cleared by the public health team."

Tragic update in search for missing man Robert Snyder
Premier Roger Cook to leave Kwinana electorate, move to Perth
Mandurah Marine Rescue's new vessel named in memory of nun who survived 1959 boating accident
Teen dies in motorbike crash at Waroona Dam
Shark alert issued after whale carcass reported at Preston Beach
Kwinana businesses to refuse serving students during school hours
Men attacked, campervan windows smashed in East Rockingham
Entries for 2026 Castaways Sculpture Awards now open
Meadow Springs man pleads guilty to threatening to kill PM and NSW Premier