Western Australia Premier Mark McGowan has tested positive for COVID-19 while isolating at home with his family.
Mr McGowan was categorised as a close contact after a family member contracted the virus, but had initially returned a negative test.
In a statement, the premier said he had taken another PCR test on Thursday and it had come back positive.
"It is not surprising considering one of my family members is positive," he said on Friday.
"In accordance with the protocols, this will extend my quarantine period until I am hopefully cleared to leave home next Thursday afternoon, at the earliest.
"I will continue to quarantine and work from home over this period."
The premier is scheduled to attend Labor's federal election campaign launch in Perth on 1 May.
Mr McGowan did not provide any details on his condition but thanked staff at testing clinics.
"I would also like to acknowledge the vital contribution of our committed health workers who have not only cared for my family, but also the many Western Australians who have been affected by this virus," he said.
COVID-19 rules set to ease in eastern states
Australia's most populous states have recorded more than 42,000 COVID-19 cases as more jurisdictions prepare to drop close contact isolation rules.
Isolation for close contacts ends in NSW at 6pm on Friday and in Victoria at 11:59pm.
Queensland will ease quarantine rules and scrap it entirely for unvaccinated international arrivals at 6pm next Thursday.
In the ACT, household contact quarantine rules will be ditched after Anzac Day (25 April) and a similar move is being considered in South Australia.
Vaccination status and check-in requirements also continue to be wound back as Victoria eases rules for pubs, restaurants, theatres and sports venues.
Vaccine mandates for workers in multiple industries are being retained in Victoria, while NSW will shift to a risk assessment-based mandate model.
More deaths linked to COVID-19 across Australia
Australia has recorded 45 more deaths related to COVID-19.
Victoria reported 16 deaths with 18,968 people testing positive for COVID-19. There are 428 people in hospital. Among them, 30 are in the intensive care unit (ICU).
In NSW, 13 people with COVID-19 have died as the state recorded 15,283 cases. There are 1,632 people in hospital and 63 of those are in ICU.
There are five people in Queensland who have died with COVID-19. The state recorded 8,080 cases and 528 of those are in hospital, including 18 who are in ICU.
In Western Australia, five people have died with COVID-19. There are 8,777 infections recorded and 258 people are in hospital with the virus, including nine in ICU.
Four people have died with COVID-19 in South Australia. There were 4,500 cases recorded, with 246 people in hospital and 10 in ICU.
Tasmania recorded two deaths, with 1,265 infections. There are 41 people in hospital, including one who is in ICU.
NT recorded 543 cases, with 46 people in hospital and one in ICU.
