The Australian government cancelled Novak Djokovic's visa for a second time on Friday, saying the world tennis No. 1, unvaccinated for COVID-19, may pose a risk to the community.

Immigration Minister Alex Hawke used discretionary powers to again cancel Djokovic'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," Hawke said in a statement.

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

The decision to again cancel his visa could set up a second court battle by the Serbian tennis star, after a court quashed an earlier revocation and released him from immigration detention on Monday.

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

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.

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

Finance Minister Simon Birmingham said on morning television on Friday that visa decisions were a matter for the country's Immigration Minister Alex Hawke, 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.

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

Fans, however, including many Serbian Australians, gave him noisy support when he was detained, anti-vaxxers have hailed him as a hero, and his family have portrayed him as a champion for individual rights.

The Committee for Melbourne, which represents business and arts leaders, says the city's reputation for hosting events has been damaged by the dispute.

"The Djokovic visa and vaccination saga has reflected poorly on all those involved, which is a tragedy considering the excellence of our infrastructure and tournament planning," Chief executive of the committee Martine Letts told The Age.