Australians have called the decision to give the tennis star a medical exemption to enter the country "a slap in the face" after they endured months of harsh lockdowns.

The number-one ranked player has repeatedly refused to say whether he has been jabbed against COVID-19, and his participation in the Australian Open was in doubt owing to the country's strict vaccination requirements.

Australian Prime Minister Scott Morrison said: "Any individual seeking to enter Australia must comply with our border requirements.

"He has to because if he's not vaccinated, he must provide acceptable proof that he cannot be vaccinated for medical reasons and to be able to access the same travel arrangements, as fully vaccinated travellers.

"So we await his presentation and what evidence he provides 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."

But in a social media post, Djokovic said: "I've spent fantastic quality time with loved ones over break & today I'm heading Down Under with an exemption permission. Let's go 2022!"

The news has not gone down well in Australia, which has endured some of the lengthiest and strictest lockdowns in the world during the pandemic. The country's borders were only reopened in November - the first time in 20 months.

Sports journalist Andy Maher wrote on Twitter: "Australians have been denied for two years, but this bloke - who's taken extraordinary liberties in the face of the coronavirus - gets his exemption.

"Novak Djokovic is an all-time great, but he ain't essential."

Several Australians responded to Djokovic on Twitter, with one saying the exemption had gone down "like a lead balloon".

One added: "A medical exemption? Very few people have medical reasons not to be vaccinated. Don't expect a good reception when you get here."

Another said: "This is insensitive to us locals, Novak. I've just had my third shot, after spending most of last year working & schooling from home, for myself, my fam & community. Victorians have done it tough. Maybe if you empathised, you'd have some support, but expect a hostile reception."

The Victoria state government had mandated that all players, staff and fans attending the Open must be fully vaccinated unless there is a genuine reason for exemption.

British tennis player Jamie Murray said: "I think if it was me that wasn't vaccinated I wouldn't be getting an exemption, but well done to him for getting clear to come to Australia and compete."

Organisers issued a statement that confirmed Djokovic will be allowed to compete in the tournament, which starts on 17 January.

"Djokovic applied for a medical exemption which was granted following a rigorous review process involving two separate independent panels of medical experts," the statement said.

"One of those was the Independent Medical Exemption Review Panel appointed by the Victorian Department of Health. They assessed all applications to see if they met the Australian Technical Advisory Group on Immunisation guidelines."

Tennis Australia said the process included the redaction of personal information to ensure privacy for all applicants.

Djokovic is not obliged to make his exemption public.

Victoria state Deputy Premier James Merlino said last month said the medical exemptions were "not a loophole for privileged tennis players".

He said the exemption applies if the person has an "acute medical condition".