INTERNATIONAL: Novak Djokovic on Tuesday warmed up for his bid to win a record 21st Grand Slam at next week's Australian Open, hitting practice shots at Melbourne Park.

A week after his arrival in Australia, Djokovic was finally able to reach the tennis court after a judge on Monday quashed the federal government's decision to cancel his visa.

But the world number one could still be detained by the federal government for a second time and deported from the country.

Australian media have reported that the Australian Border Force was investigating potential discrepancies in the traveler form submitted by Djokovic, and his whereabouts in the days before he arrived in Australia.

In the document submitted to court, Djokovic ticked "no" when asked if he had been overseas in the 14 days prior. Social media posts, however, appeared to show him in Belgrade on Christmas Day and then in Spain only days before his trip to Australia.

Videos from January 2 showed Djokovic training and interacting with a young tennis player at the Club de Tenis Hotel Puente Romano in Marbella.

In the Spanish capital Madrid, Spain's foreign minister said he had no information on whether Djokovic had visited Spain before travelling to Australia.

Victorian Premier, Daniel Andrews, whose state hosts the Australian Open, said the issue surrounding Djokovic's visa was still under a "very active process."

Australia has a policy barring non-citizens or non-residents from entry unless they are fully vaccinated against Covid-19. The government allows for medical exemptions, but it has argued that Djokovic, who is not vaccinated, did not provide adequate justification for an exemption.

The court on Monday ruled Djokovic was treated unfairly by border force officials on his arrival and ordered his visa cancellation be overturned. The court did not, however, address whether his exemption - based on Djokovic contracting Covid-19 last month - was valid.

Public opinion in Australia, which is currently battling a wave of Covid-19 Omicron infections, and where more than 90% of the adult population is double vaccinated, has been largely against the player.

Keith Moore, Melbourne resident said: "I am appalled. The judges seem to have no understanding of public requirements in respect to Djokovic. He's a selfish, non-vaccinated and I think he strays from the truth and the sort of understanding in respect of COVID that all us Victorians have lived through and I think he should be sent back on the next plane and his father should have a good word with him."

 Jason Robinson, Melbourne resident has stated:

"So if he plays, I think in all the Djokovic matches at the tennis, I think the two most important words that need to be practiced by the umpires are 'quiet please,' because I think he's going to cop a lot. And do I support that? Between you and me secretly, yeah a little bit, it's the Aussie way, right, give it to him."