The Serbian sports superstar was hoping to win his 21st Grand Slam at the Australian Open later this month, but on Sunday he began his fourth day in immigration detention in Melbourne.
A vocal opponent of vaccine mandates, Djokovic had declined to reveal his vaccination status or reason for seeking a medical exemption for sidestepping Australia's vaccine rules. He broke his silence on Saturday by filing a legal challenge saying he was granted an exemption due to contracting - and recovering from - the virus in December.
The Australian government has said its health department notified Australian Open organising body Tennis Australia last November that a recent COVID-19 infection was not necessarily grounds for exemption in the country, as it was elsewhere.
Djokovic's lawsuit says the Department of Home Affairs wrote to him this month to say he had satisfied the requirements to enter the country.