Tennisumpire Carlos Bernardes suffered a heart attack during his quarantine period in Melbourne, according to local media. Bernardes would be fine and leave the hospital again on Saturday.
The Brazilian Bernardes was several times the umpire at a final at a grandslam tournament. In 2011, he was the referee in the Wimbledon final battle between Rafael Nadal and Novak Djokovic.
In the run-up to the Australian Open, tennis players and other outside players are quarantined in Melbourne for two weeks. Players are allowed to spend five hours a day in their hotel room to train. Dozens of tennis players have to stay in their room during the quarantine, because on their flight to Melbourne someone tested positive.
The Australian Open starts on Monday 8 February.