A lawyer says there are two possible reasons why Novak Djokovic’s visa may have been torn up.

Australian Catholic University’s Dean of Law, Professor Patrick Taser, says one possibility is that he just applied for the wrong visa.

“Given he’s been here so many times you’d think his team would be sophisticated enough to apply for the correct one,” he told Tony Jones.

The second possibility is that Australian Border Force isn’t satisfied that the world number one’s medical exemption is genuine.

“Just because Novak Djokovic has gotten a medical exemption from Tennis Australia, it doesn’t mean that he’s allowed entry into the country,” Professor Taser said.

“One would have hoped that Tennis Australia and Border Force would have engaged in some coordination … but that appears not to have happened.

“It appears that the medical exemption has been granted by the Tennis Australia independent panes but that doesn’t close up the possibility that Border Force could come to a different view.”

Press PLAY below to hear more about the possible legal reasons behind the visa cancellation