Melbourne, Jan 7 (IANS): World No. 1 tennis player Novak Djokovic's visa being cancelled on his arrival in Melbourne to play in the season-opening Grand Slam, has the potential of turning into a diplomatic crisis between Australia and Serbia.

Australian Prime Minister Scott Morrison had re-iterated on Thursday that nobody was above the country's border rules as he ordered cancellation of Djokovic's visa. "Mr Djokovic's visa has been cancelled. Rules are rules, especially when it comes to borders. No one is above these rules," Morrison had tweeted.

On Friday, as the defending Australian Open champion's lawyers tried to get the decision reversed, Serbian president Aleksander Vucic spoke to the media, hitting out at the supposed politics behind Djokovic's detainment.

Djokovic will continue to remain in the Carlton Hotel here until his court hearing resumes on January 10. The Serbian has never spoken publicly about his vaccination status. Australia is seeing tens of thousands of COVID-19 cases for the first time after enduring some of the world's strictest restrictions.

"What is not fair-play is the political witch hunt (being conducted against Novak), by everybody including the Australian Prime Minister pretending that the rules apply to all," sen.com.au quoted Vucic telling the media on Friday.

"I fear that this relentless political pursuit of Novak will continue until the moment they can prove something, because when you cannot defeat somebody then you turn to these type of things," added Vucic.

The nine-time Australian Open champion had entered the country "claiming to have COVID-19 in the last six months, thus providing him a medical exemption to the vaccine". However, the Federal officials were not convinced with Djokovic's documentation to prove he had the virus, and subsequently cancelled his visa.

Vucic added that Serbia would "continue to follow up the case with the Australian government".

Meanwhile, Djokovic's father, Srdjan, said in Belgrade, that his son was a victim of "political oligarchy".

"Our Novak, our pride. Novak is Serbia and Serbia is Novak," he said. "They are trampling over Serbia and by doing that, they are trampling on the Serbian people. The leader of that faraway land, Scott Morrison… dared to attack Novak and expel him before he had reached their country. They had wanted to throw him to his knees, and not just him, but our beautiful Serbia.

"We Serbs are a proud European people. Throughout history, we have never attacked anyone, we only defended ourselves. That is what Novak, our pride, our Serb, the pride of the entire free world, is now doing by his behaviour towards hosts and (tournament) organisers across the world, showing what kind of people he comes from," Srdjan was quoted as saying by sen.com.au.

Djordie Djokovic, Novak's brother, suggested Tennis Australia was behind the mess. "He had the same document as several tennis players who are already in Australia. Novak and his team had no way of contacting federal authorities. He was taken to a migrant hotel to a dirty room without any belongings, which he was told would be returned to him upon his return to Europe.

"He was treated like a criminal while he is a healthy and decent man and a sportsman who has not endangered anyone's life and has not committed any federal or legal offence," said Djordie.