World tennis number one Novak Djokovic won a shock victory in his bid to remain in Australia Monday, with a judge ordering his immediate release from immigration detention.

Judge Anthony Kelly abruptly ended days of legal wrangling, after the state dropped its decision to revoke Djokovic's visa.

But a government lawyer warned that Australia may yet use ministerial powers to order Djokovic's removal from the country, which would result in him being banned for three years.

With the Australian government facing a humiliating and high profile defeat, lawyer Christopher Tran informed the judge that immigration minister Alex Hawke may step in with executive powers.

"I'm instructed (the minister) will consider whether to exercise a personal power of cancellation," he said.

The 34-year-old world number one arrived in Melbourne last week ahead of the Australian Open, hoping to win a record-breaking 21st Grand Slam title.

But officers at Melbourne's Tullamarine Airport decided the unvaccinated star had failed to present a solid medical reason for not being jabbed.

Djokovic's visa was revoked and he was moved to a immigration detention facility pending deportation.

(FRANCE 24 with AFP)