Players hoping to participate in the Australian Open must be vaccinated or qualify for an exemption.
Djokovic, who is the defending champion, refused to reveal his vaccination status as doubts about his participation continued to grow.
The world number one recently revealed on his social media channels that he has received an exemption and was heading to Melbourne for the Grand Slam.
However, just as Djokovic looked set to defend his crown, Australia's Prime Minister cast further doubt as he questioned the Serbs exemption saying: "We await his presentation and what evidence he provides us to support that.
"If that evidence is insufficient, then he won't be treated any different to anyone else and he'll be on the next plane home.
"There should be no special rules for Novak Djokovic at all. None whatsoever."
The country's Home Affairs minister, Karen Andrews, added: "Australian Border Force will continue to ensure that those who arrive at our border comply with our strict border requirements.
"No individual competing at the Australian Open will be afforded any special treatment."
Despite pressure on Djokovic to reveal more information about the reasons for his exemption, the director of Australian Open said that it is up to the player to publicly reveal his status.
Craig Tiley said: "We completely understand and empathise that some would have been upset by the fact that Novak Djokovic has come in because of his statements around vaccination in the past couple of years."
"We would love…Novak to talk about it and help us with it, but ultimately it's going to be up to him.
"We aren't in a position, even legally, to disclose other people's medical information."