Australian High Commissioner George Brandis has no coronavirus symptoms after hosting one of the last official functions attended by the now sick Prince of Wales.
Heir to the throne Charles, 71, is displaying "mild symptoms" of the illness but is in good health and spirits as he self isolates at Birkhall in Scotland, a spokesman said.
It's believed one of the last official engagements the Prince attended was an Australian bushfire fundraiser by Mr Brandis' at Mansion House in London on March 12.
But Australia House spokesman says the high commissioner, 62, has no symptoms and is following UK government guidelines.
"All of us at the Australian High Commission wish His Royal Highness a speedy recovery," the spokesman said in a statement on Wednesday.
The Prince's Clarence House office can't pinpoint whether Charles had picked up the infection at the fundraiser or not.
"It is not possible to ascertain from whom the Prince caught the virus owning to the high number of engagements he carried out in his public role during recent weeks," a spokesperson said.
The Prince's wife Camilla, 72, who is also at Birkhall, in Aberdeenshire, has tested negative for the virus, so is separating herself from the prince.
Doctors believe future king Charles became contagious on March 13, the day after he last saw his mother, the Queen.
Buckingham Palace said the 93-year-old monarch, who is staying at Windsor Castle with the 98-year-old Duke of Edinburgh, remains in good health and is following all appropriate advice.
Philip was not with the Queen at Buckingham Palace when she last met Charles on March 12.