Novak Djokovic is expected to find out if he can play in this year’s Australian Open on Monday.

But whatever the outcome of the Serb’s court case, the controversy surrounding the world No.1 tennis player will not subside any time soon.

The federal government has even warned that Djokovic could have his visa cancelled again.

The highly anticipated case will play out in the Federal Court from 10am after the Morrison government failed in its bid to delay the hearing by two days.

Ahead of the hearing, Djokovic’s parents have joined a protest rally in downtown Belgrade where they claimed their son is being held in Melbourne without access to meals.

“Today is a big day. Today, the whole world will hear the truth,” said Djokovic’s mother, Dijana Djokovic.

“We hope that Novak will come out as a free man. We send great love to Novak. We believe in him, but also in the independent judiciary in Melbourne.”

Mrs Djokovic said conditions in the hotel where Djokovic is staying are “not humane”.

“He doesn’t even have breakfast,” she said. “He has a wall to stare at and he can’t even see a park in front or go out of the room.”

Documents lodged with the Federal Court on Saturday allege the 34-year-old tennis star had tested positive to COVID-19 on December 16 and was consequently given a medical exemption by Tennis Australia to compete as an unvaccinated player.

But on the same day of his positive PCR test, reports in the Serbian media show a maskless Djokovic attending a ceremony at the Serbian national post office to receive his own stamp.

It’s unclear if he received his result before he attended the event, but France24 reports that a day later he also attended an event without a mask to give awards to top junior players.

And he met a senior government minister on the same day.

It comes as Tennis Australia boss Craig Tiley revealed to The Age and Sydney Morning Herald that Tennis Australia asked the federal government on two occasions in November to examine each of the handful of exemptions that TA and the Victorian government granted to unvaccinated players in order for them to enter the Open.

“They declined,” Mr Tiley said.

“We asked if they could please assess our decisions. We said we’re going to need some help to make sure we’re doing the right thing.

“We’d be in a different situation today.”

Tweet from @DjokerNole

Djokovic was detained on Thursday evening in a high-profile case after the Australian Border Force cancelled his visa for failing to provide sufficient evidence to meet Australia’s entry requirements.

He is being held at the Park Hotel in Melbourne, where some asylum seekers who have been held in detention for more than nine years are also staying.

Australian tennis star Nick Kyrgios says Djokovic has been treated inhumanely.

“Look I definitely believe in taking action. I got vaccinated because of others and for my mum’s health, but how we are handling Novak’s situation is bad, really bad,” Kyrgios said on Twitter.

“Like these memes, headlines, this is one of our great champions but at the end of the day, he is human. Do better.”

Australians protest against Djokovic’s detention in Melbourne. Photo: Getty

On Sunday, federal Health Minister Greg Hunt declined to comment on the Djokovic case at a media conference.

But he noted that several other players involved at the Australian Open, including Czech player Renata Voracova who was detained in the same hotel as Djokovic, have had their visas revoked.

Voracova left the country without challenging her status, the Czech Foreign Ministry said.