Novak Djokovic's visa has been cancelled and his Australian Open campaign is in tatters. 

The tennis star was told to leave the country today but reports suggest he will challenge the decision in Victoria's courts. 

The world number one touched down on an Emirates flight from Dubai into Melbourne shortly after 11pm Wednesday night AEST. 

His father Srdjan reportedly told a Serbian radio station that his son was "isolated in a room" at the airport without his entourage and was being held under police guard. 

'Fair dinkum disgrace': Australia reacts to Djokovic vax exemption 

Srdjan later released an explosive statement to Serbian media. 

"I have no idea what's going on, they're holding my son captive for five hours," he said. "This is not 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 everybody." 

Even Serbian president Aleksandar Vucic became involved, calling Djokovic and providing an update via an Instagram post 

"Just got off the phone with Novak. I told our Novak that the whole of Serbia is with him, and that our authorities are taking all measures to stop the harassment of the best tennis player in the world in the shortest possible period," Vucic said. 

"In accordance with all the norms of international public law, Serbia will fight for Novak Djokovic, for justice and truth. 

"Otherwise, Novak is strong, as we all know him." 

However, shortly after the president weighed in, Djokovic's visa was cancelled. 

Visa complications behind Djokovic delay 

A federal government source told The Age there were issues regarding the documentation required to prove the reason for Djokovic's exemption, which is required from unvaccinated people. 

Djokovic was believed to be relying on the fact that he has had Covid within the past six months however the source said it was unclear if that was sufficient to secure entry under federal guidelines. 

Some reports suggested a member of Djokovic's team may have filled out the incorrect visa application for him, which does not apply to people who have received vaccination exemptions. 

Earlier the Victorian Government tweeted saying it was rejecting Djokovic's entry because he was on a work visa which requires the support of the state government. 

Acting Sports and Major Events Minister Jaala Pulford tweeted at 11.14pm that the Victorian Government would not support Djokovic's application. 

"The Federal Government has asked if we will support Novak Djokovic's visa application to enter Australia," she said. 

"We will not be providing Novak Djokovic with individual visa application support to participate in the 2022 Australian Open Grand Slam. 

"We've always been clear on two points: visa approvals are a matter for the Federal Government, and medical exemptions a matter for doctors."