MELBOURNE (REUTERS, AFP) - The Australian government cancelled Novak Djokovic's visa for a second time on Friday (Jan 14), saying the tennis world No. 1 - who remains unvaccinated against Covid-19 - may pose a risk to the community.

Immigration Minister Alex Hawke used discretionary powers to again cancel the Serb's visa, after a court quashed an earlier revocation and released him from immigration detention on Monday.

"Today I exercised my power under section 133C(3) of the Migration Act to cancel the visa held by Mr Novak Djokovic on health and good order grounds, on the basis that it was in the public interest to do so," Mr Hawke said in a statement.

Under the section of the Migration Act which the minister used to exercise his power to cancel the visa, Djokovic would not be able to secure a visa to come to Australia for three years, except in compelling circumstances that affect Australia’s interest.

The decision to again cancel the visa also set up a second court battle by the Serbian tennis star. 

Following the decision, Djokovic’s lawyers asked an Australian court for an injunction to block the government from deporting the Serb.

The lawyers spoke at a late night hearing at the Federal Circuit and Family Court of Australia before Judge Anthony Kelly, the same judge who on Monday quashed an earlier cancellation of Djokovic’s visa.

According to Reuters, they want their challenge to the visa revocation to be heard by Sunday, so that Djokovic can play in the Australian Open when the Grand Slam starts on Monday.

Djokovic, the defending champion, had spent the early part of Friday on an empty court at Melbourne Park practising.

He had been included in Thursday's draw as top seed and was due to face fellow Serb Miomir Kecmanovic for his opening match, probably on Monday or Tuesday.

Earlier, Melbourne's The Age newspaper cited a source in Prime Minister Scott Morrison's Liberal Party as saying that the government was "strongly leaning" towards revoking the visa again.

Mr Morrison said after the decision that his government cancelled Djokovic’s visa to protect Australia’s hard-won gains against the Covid-19 pandemic.

“Australians have made many sacrifices during this pandemic, and they rightly expect the result of those sacrifices to be protected,” he said in a statement.

"This is what the minister is doing in taking this action today. Our strong border protection policies have kept Australians safe.

"Due to the expected ongoing legal proceedings, I will be not be providing any further comment.”

Djokovic, a vaccine sceptic, fuelled widespread anger in Australia when he announced last week he was heading to Melbourne for the Australian Open with a medical exemption to requirements for visitors to be inoculated against Covid-19.

On arrival, the Australian Border Force decided his exemption was invalid and put him in an immigration detention hotel alongside asylum seekers for several days.

Judge Kelly on Monday allowed him to stay on the grounds that officials had been “unreasonable” in the way they handled his interview in a seven-hour process in the middle of the night when he was detained at the Melbourne airport.

Djokovic’s cause was not helped by a mistake in his entry declaration relating to overseas travel in the prior two weeks, which he attributed to his agent. He also acknowledged he should have rescheduled an interview and photoshoot for a French newspaper on Dec 18 while infected with Covid-19.

Australia has endured some of the world's longest lockdowns, has a 90 per cent vaccination rate among adults, and has seen a runaway Omicron outbreak bring nearly a million cases in the last two weeks.

An online poll by the News Corp media group found that 83 per cent favoured the government trying to deport the tennis star.

“Absolutely, he should go. He hasn’t done the right thing and is being a bit cheeky about it,” said Venus Virgin Tomarz, 45, who lives in Melbourne.

“To be honest, it’s political. But if what the media are saying is true – that he didn’t come with the right paperwork - he should be treated just like everyone else,” said Jacob Coluccio, 25, who also lives in Melbourne.

Finance Minister Simon Birmingham said on morning television on Friday that visa decisions were a matter for the country's Immigration Minister, but the policy settings of the government overall were "crystal clear".

"That is that people who enter Australia who are not Australian citizens should be double dose vaccinated unless they have a clear and valid medical exemption against that," he said on Channel 9's Today Show.

Greek world No. 4 Stefanos Tsitsipas had said Djokovic was “playing by his own rules” and making vaccinated players “look like fools”.

“No-one really thought they could come to Australia unvaccinated and not having to follow the protocols... it takes a lot of daring to do and putting the Grand Slam at risk, which I don’t think many players would do,” Tsitsipas said in an interview with India’s WION news channel.

“The stats say 98 per cent of players have been vaccinated and did what they had to do in order to come and perform and play in Australia."