Australian Open players have been told not to feed mice at the quarantine hotel in Melbourne after one player complained of rodents in her room.
Yulia Putintseva, the world number 28, swapped rooms after finding a mouse but said her new room is also infested.
The 26-year-old is among more than 70 players and their entourages confined to their hotel rooms for 14 days.
Victoria state police minister Lisa Neville "encouraged" players to "minimise interaction" with the mice.
"As I understand, there may have been some feeding going on," Neville added, without giving further details.
"We will keep doing pest control if we need to, but hopefully that pest control work that was done this week will have fixed the problem."
Neville also said 10 people in total who have flown to Melbourne for the tournament had now tested positive for coronavirus, with three new cases on Wednesday comprising two players and a support person.
Kazakhstan's Putintseva - who was among the first players to complain about the hotel quarantine rules for the Grand Slam event - again used social media to post a video of a mouse in her room jumping out from behind a cupboard.
Putintseva says she has lost sleep because of the rodents scurrying around, and also expressed frustration about being unable to open a window in her room.
"We need fresh air to breathe," she posted on Instagram.
A total of four players, have now tested positive for the virus according to officials, but there has been confusion over the figures with several test results later reclassified by authorities as "viral shedding" from previous infections, meaning they are not contagious.
The row over quarantine rules and allowances afforded to travelling players compared to residents, has cast huge controversy over the year's first major tennis tournament.
Tennis Australia chief executive Craig Tiley said a "tightrope" was being walked, but that the safety of Victorians would not be compromised.
"I do understand the players, this is a new experience for them and I don't think anyone expected to know what the 14 days was like and they are adapting to it," he told ABC News Breakfast.
"At the beginning, it was pretty challenging with their adaptation It's got a lot better, I think the majority of the players understand and accept it and there is a minority struggling with it but we are going to do whatever we can to make it better for them."