Lewis Hamilton self-isolated after being at an event with two people who have tested positive for coronavirus, though the six-time Formula One champion assured fans he was "doing well" and had "zero symptoms".

There were fears the Briton could have contracted COVID-19 after he was pictured at an event in London earlier this month with actor Idris Elba and Sophie Gregoire Trudeau, the wife of Canadian prime minister Justin Trudeau, both of whom have since tested positive for coronavirus.

Hamilton explained that he has been in isolation as a precaution since last Friday, shortly before the Australian Grand Prix – the opening race of the new F1 season – was postponed.

However, the 35-year-old Mercedes driver said he has not been tested due to the limited number of tests available and stressed he was not showing any signs of the virus.

"There's been some speculation about my health after I was at an event where two people later tested positive for coronavirus," Hamilton wrote in a message uploaded to his social media accounts.

"I wanted to let you know that I'm doing well, feeling healthy and working out twice a day. I have zero symptoms and it's now been 17 days since I saw Sophie and Idris. I have been in touch with Idris and happy to hear he is okay.

"I did speak to my doctor and double checked if I needed to take a test but the truth is there is a limited amount of tests available and there are people who need it more than I do, especially when I wasn't showing any symptoms at all.

"So what I've done is keep myself isolated this past week, actually since practice was cancelled last Friday and kept my distance from people."

Hamilton had initially expressed shock that the F1 season had been due to start on time in Melbourne last weekend despite many other events being cancelled owing to the coronavirus pandemic.

The Australian Grand Prix was eventually called off after one of McLaren's crew members tested positive for COVID-19.

Subsequent races in Bahrain, Vietnam, China, the Netherlands and Spain have been postponed while the Monaco Grand Prix has been scrapped entirely for 2020.

The earliest the F1 season can now begin is on June 7 in Baku.