Serbia's president has accused Australia of "harassing" men's world number one tennis player Novak Djokovic after he was denied entry to the country because he is not vaccinated against COVID-19.

The Serbian tennis star flew in to the Victorian capital Melbourne on Thursday ahead of the Australian Open tournament, which starts on January 17.

Djokovic, who has consistently refused to disclose his vaccination status while publicly criticising mandatory vaccines, kicked off a furore when he said on Instagram on Tuesday he had received a medical exemption to pursue a record-breaking 21st Grand Slam win at the Open.

He is now in a quarantine hotel in Melbourne after his lawyers secured an agreement for him to remain in the country for a court hearing on Monday in his case to overturn the federal government ban on his entry.

"There are no special cases, rules are rules," Australian Prime Minister Scott Morrison said at a televised news briefing. "We will continue to make the right decisions when it comes to securing Australian borders in relation to this pandemic."

FEDERAL SYSTEM

Under Australia's federal system, states and territories can issue exemptions from vaccination requirements to enter their jurisdictions. However, the federal government controls international borders and can challenge such exemptions.

Djokovic travelled to Australia after receiving an exemption from the Victorian government. That exemption – the reasons for which are not known – supported his federal government-issued visa.

On his arrival, however, Federal Border Force officials at the airport said Djokovic was unable to justify the grounds for his exemption.

But that has caused harsh words between Canberra and Belgrade.

Serbian President Aleksandar Vucic said on Twitter he had spoken with Djokovic, giving the reassurance "that the whole of Serbia is with him and that our bodies are doing everything to see that the harassment of the world's best tennis player is brought to an end immediately."

Morrison said he was aware that "representations have been made" by the Serbian embassy in Canberra and denied the claims of harassment.

NOVAK IS "SPARTACUS"

Djokovic's father told media in Serbia that his son was ushered into an isolation room under police guard when he touched down at Melbourne's Tullamarine airport at about 11:30 p.m. (1230 GMT) on Wednesday after a 14-hour flight from Dubai.

"They can incarcerate him tonight and shackle him tomorrow, but truth is like water as it always finds its way," Srdjan Djokovic said, in comments quoted on the Telegraf newspaper's website. "Novak is the Spartacus of the new world that does not tolerate injustice, colonialism and hypocrisy."

Spanish champion Rafael Nadal told reporters in Melbourne that he felt sorry for Djokovic "but at the same time, he knew the conditions since a lot of months ago. He makes his own decision."