(CNN) — Nine-time Australian Open champion Novak Djokovic may not be able to defend his 2021 title after his visa to enter Australia was canceled following an outcry over his controversial “medical exemption” from the country’s coronavirus vaccination rules.

Djokovic, the men’s tennis world no.1, hasn’t publicly revealed his vaccination status — but in a news conference on Thursday, Australian Prime Minister Scott Morrison said he “didn’t have a valid medical exemption” to the vaccination requirement for all arrivals.

“Entry with a visa requires double vaccination or a medical exemption,” Morrison said. “I am advised that such an exemption was not in place, and as a result, he is subject to the same rules as everyone else.”

“There are many visas granted, if you have a visa and you’re double vaccinated you’re very welcome to come here,” he added. “But if you’re not double vaccinated and you’re not an Australian resident or citizen, well, you can’t come.”

The 34-year-old traveled to Melbourne after tournament organizers, in conjunction with the Victoria Department of Health, said he had been granted a medical exemption to play but he was blocked at the border and told he had not met the required entry rules.

Health Minister Greg Hunt said Thursday it was up to Djokovic whether he wanted to appeal the decision — “but if a visa is canceled, somebody will have to leave the country.”

Djokovic’s legal team sought an urgent injunction against the Australian Border Forces’ decision to revoke his visa. The country’s Federal Court has adjourned the decision until Monday on whether he will be allowed to remain in Australia or be deported, according to Reuters and public broadcaster ABC.

Djokovic will be staying in Australia overnight as the injunction goes through the courts, ABC reported.

On Thursday, supporters of Djokovic gathered outside the Park Hotel in Melbourne, where he was allegedly transferred after being detained at the airport, according to CNN affiliates Seven Network and Nine News. The hotel was formerly used as a Covid-19 quarantine hotel for returned travelers, but is now operating as a detention facility housing asylum seekers and refugees.

Djokovic has previously voiced opposition to compulsory Covid-19 vaccines, saying he was personally “opposed to vaccination” during a Facebook live chat. He contracted the virus in June 2020, but since then there have been no reports of him being re-infected.

The controversy comes as Australia faces a growing outbreak, having reported a record high number of daily new cases for several days in a row.

Tournament organizers earlier said the Serb, who is trying to break the record for most men’s grand slam singles titles, had received a medical exemption to play in the prestigious tennis tournament.

The exemption was met with controversy as Djokovic traveled to Melbourne on Wednesday.

According to Australian news outlets The Age and The Sydney Morning Herald, the Australian Border Force (ABF) contacted the state Victoria government after learning of an issue with the visa submitted by Djokovic’s team while he was en route to the country.

The ABF confirmed in a statement that the 34-year-old player’s visa had been revoked for failing to provide appropriate evidence for entry to the country.

“The Australian Border Force will continue to ensure that those who arrive at our border comply with our laws and entry requirements,” the statement read.

After the decision was confirmed, Morrison tweeted that Djokovic was subject to the same rules as everyone. “Rules are rules, especially when it comes to our borders. No one is above these rules. Our strong border policies have been critical to Australia having one of the lowest death rates in the world from Covid, we are continuing to be vigilant,” he wrote.

Players were told they would have to be fully vaccinated in order to participate or have a medical exemption granted by an independent panel of experts.

The vaccine exemption sparked backlash in Australia.

Deputy Victorian Liberal Leader David Southwick called the decision to allow Djokovic to take part in this year’s tournament “a disgrace,” describing it as a “kick in the guts to every Victorian” who endured months of lockdowns and suffered personal setbacks during the pandemic.

As events unfolded, Djokovic’s father, Srdjan Djokovic, told a Serbian radio station his son was being held “captive” by Australian officials following a visa application mix-up.

He told Serbian radio station B92 his son was being housed in a room that no one can enter, with two policemen in the front of the room.

“I have no idea what’s going on. They’re holding my son captive for five hours,” Srdjan Djokovic said in a statement to Russian news agency Sputnik, according to B92. “This is a fight for the libertarian world, this is not just a fight for Novak, but a fight for the whole world! If they don’t let him go in half an hour, we will gather on the street. This is a fight for everyone.”

Since the comments were made, there have been no reports of any gatherings in Belgrade or outside the Melbourne Airport.

Earlier on Wednesday, Djokovic’s coach Goran Ivanisevic posted a photo to social media from what appears to be the Melbourne Airport in Australia where Djokovic reportedly was being held, captioning it, “Not the most usual trip Down Under.”

The Australian Open is set to run from January 17-30.

Organizers say two panels reviewed exemption application

Djokovic has voiced opposition to compulsory Covid-19 vaccines.

“Personally, I am opposed to vaccination and I wouldn’t want to be forced by someone to take a vaccine in order to be able to travel,” he said in a Facebook live chat, according to Reuters.

But in May of last year, Djokovic said vaccination was a matter of personal choice: “I will keep the decision as to whether I’m going to get vaccinated or not to myself. It’s an intimate decision, and I don’t want to go into this game of pro and against vaccines, which the media is unfortunately creating these days.”

Australian Open organizers said in a statement on Tuesday that Djokovic’s exemption was “granted following a rigorous review process involving two separate independent panels of medical experts.”

During a news conference Wednesday, CEO of Tennis Australia Craig Tiley defended the impartiality of the medical exemption review process, telling reporters, “No one knew who the applicant was.”

Calls for a boycott

Across Melbourne, one of the world’s most locked-down cities in 2021, tennis fans took to social media posting calls for an Australian Open “boycott.”

The backlash against the exemption comes after Melbourne residents spent more than 260 days confined to their homes, forbidden to leave except to buy groceries or other essential items, mostly in two long stretches from July to October, 2020 and August to October, 2021.

Australia has started 2022 with a record number of new Covid-19 cases due to a growing outbreak centered in the eastern states.

New South Wales, the most populous state, and Victoria — home to Melbourne — both posted daily record case numbers on Saturday, health department figures showed.

Exemption conditions

Under the Australian Technical Advisory Group on Immunisation’s (ATAGI) current guidelines, a medical exemption is granted to individuals who have an “acute major medical condition (e.g. undergoing major surgery or hospital admission for a serious illness.”

The other remaining grounds for a medical exemption concern people who have suffered a “serious adverse event attributed to a previous dose of a Covid-19 vaccine, without another cause identified” and a vaccinee who “is a risk to themselves or others during the vaccination process,” due to an “underlying developmental or mental health disorder.”

Lastly, exemptions may be given to anyone with a “PCR-confirmed SARS-CoV-2 infection, where vaccination can be deferred until six months,” and in cases where individuals have received “anti-SARS-CoV-2 monoclonal antibody or convalescent plasma therapy.”

“It’s ultimately up to him to discuss with the public his condition if he chooses to do that and the reason why he received his exemption,” Tiley said.

The-CNN-Wire™ & © 2021 Cable News Network, Inc., a Time Warner Company. All rights reserved.

Join our Newsletter for the latest news right to your inbox