Scott Morrison says he has tested positive to COVID-19 but will continue to discharge all his responsibilities as prime minister.
"I am experiencing flu-like symptoms and will be recovering over the next week," Mr Morrison said in a statement announcing that he had tested positive on Tuesday night.
"I had tested myself daily since Sunday, including this morning, with all tests returning a negative result," he said.
"I took a further test this evening after developing a fever late today. The test was inconclusive so I took a PCR test tonight which returned a positive result late this evening."
Mr Morrison said he was isolating at home in Sydney and "continuing to follow health guidelines".
He said his wife and children had tested negative and will isolate for seven days at home as close contacts.
"While in isolation I will continue to discharge all my responsibilities as Prime Minister... focusing on our emergency response to the devastating floods in Queensland and New South Wales, and ensuring we stand with each and every one of the affected communities both now and as the waters eventually recede," he said.
He added he would be "focused on our urgent response to the tragedy unfolding in the Ukraine and Russia's senseless aggression, staying in regular contact with our security and intelligence officials and our international partners, as well as working with the Treasurer to finalise the budget".