The Australian Open was plunged into a crisis on Saturday as positive COVID-19 cases were detected on two charter flights into Melbourne, forcing 47 players into hard lockdown for a fortnight.
Tournament officials said two passengers on a flight from Los Angeles that arrived on Friday morning had tested positive, along with one passenger who travelled in from Abu Dhabi.
None of those who tested positive were said to be players, although one was described as a "participant", which may mean a member of a player's entourage.
About 1,200 players and staff are arriving in Melbourne ahead of the delayed Australian Open, which is due to get under way on February 8.
They are travelling on sparsely populated aeroplanes to allow for social distancing, with 79 people, including 24 players, aboard the flight from Los Angeles and 64 people, including 23 players, arriving from Abu Dhabi. It was reported that players affected included recent grand slam champions.
A statement from the Australian Open said the players "will not be able to leave their hotel room for 14 days and until they are medically cleared. They will not be eligible to practise."
Australia's Department of Health and Human Services (DHHS) said those aboard the flights were considered 'close contacts' of those with the virus, and that means they will be confined to their hotel bedrooms for the next two weeks.
The Australian Open has pulled out all the stops in an effort to get the grand slam on, and that has meant all players have had to arrive early and go into quarantine, although most will be allowed to spend five hours outside their hotel rooms each day, to allow for practice and gym work.
Such limited liberties will not be afforded to those hit by the news of the positive tests on their flights.
French player Alize Cornet questioned why such steps were necessary, writing on Twitter: "Soon, half of the players from the AO will actually have to isolate. Weeks and weeks of practice and hard work going to waste for one person positive to Covid in a 3/4 empty plane. Sorry but this is insane."
The 30-year-old world number 53 added: "I just think that these measures are not made to hold an international tennis event."
Cornet, who said she was not on an affected flight, believed there were meant to be measures in place to avoid wholesale lockdown in the case of positive tests.
She said: "We've been told that the plane would be separated by section of 10 people and that if one person of your section was positive, then you had to isolate. Not that the whole plane had to."
Victoria on Saturday recorded its 10th consecutive day with no locally acquired cases of coronavirus.