The Australian government hit back hard at tennis star Novak Djokovic’s assertion that he was assured entry with a medical exemption from coronavirus vaccine requirements, pointing out in court papers filed Sunday that no foreigner has a guaranteed right to enter the country.

“There is no such thing as an assurance of entry by a non-citizen into Australia. Rather, there are criteria and conditions for entry, and reasons for refusal or cancellation of a visa,” the government said in a filing ahead of a court hearing on the case on Monday.

Djokovic has been confined in a hotel used for asylum seekers and is challenging the decision to cancel his visa after being stopped on arrival at Melbourne Airport early on Thursday. A vocal opponent of Covid-19 vaccine mandates, he said in a filing to the court on Saturday that he been granted an exemption from vaccination due to having had the virus in December.

His lawyers said he had the necessary permissions to enter Australia, including an assessment from the Department of Home Affairs that responses on his travel declaration form indicated he met the conditions for quarantine-free arrival. The government disputed this.

It said the department’s email was not an assurance “that his so-called ‘medical exemption’ would be accepted”, and his responses could be questioned and verified on his arrival. The government also challenged Djokovic’s claim for a medical exemption on the basis he had contracted Covid-19 in mid-December and had recovered two weeks later.

“There is no suggestion that the applicant had “acute major medical illness” in December 2021. All he has said is that he tested positive for Covid-19. This is not the same,” the filing said.

French newspaper L’Equipe published a photograph of the player taken when he was named the daily’s Champion of Champions in the days after he said in the court filing he had tested positive for coronavirus on December 16. Other photographs published on social media showed him appearing at functions in Serbia on dates soon after that test.

It was not clear if Djokovic knew of his positive test at the time of the events.

Djokovic’s lawyers will have up to two hours to present their case from 10 am (local time) on Monday, while the government department gets two hours to present its defence from 3 pm.

The government filing on Sunday stressed that even if the court ruled to free Djokovic from detention and let him play in the Open, under Australian law the government had every right to detain him again and remove him from the country because he is a non-citizen.

That drew particular ire from Djokovic’s father, who addressed another small protest in front of Serbia’s parliament building in Belgrade on Sunday. Srdjan Djokovic said: “Are we animals? What are we? We’re human beings. This is happening because we are just a small part of the world, but we are proud. They have no respect for him.”

Australia says its health department notified tournament organising body Tennis Australia in November that a recent Covid-19 infection was not necessarily grounds for exemption in the country.

Tennis Australia CEO Craig Tiley said his organisation had spoken with federal and state officials for months to ensure the safe passage of players. “We were talking to all parts of government to ensure that ... we were doing the right thing and following the right process with these exemptions,” Tiley told Channel Nine television.

Czech player Renata Voracova who was also detained and had her visa revoked after issues with her vaccine exemption, left the country without challenging her status.