Russian and Belarusian flags have been banned from the Melbourne Park precinct during the Australian Open after a complaint from the Ukraine ambassador to the country.
Vasyl Myroshnychenko, Ukraine's ambassador to Australia and New Zealand, posted a picture showing a Russian flag hanging from a bush beside the court where his compatriot Kateryna Baindl was playing her first-round match on Monday.
"I strongly condemn the public display of the Russian flag during the game of the Ukrainian tennis player Kateryna Baindl at the Australian Open today," he wrote on Twitter.
"I call on Tennis Australia to immediately enforce its 'neutral flag' policy."
Tennis Australia responded on by banning the flags of the two countries.
"Flags from Russia and Belarus are banned onsite at the Australian Open," Tennis Australia said in a statement.
"Our initial policy was that fans could bring them in but could not use them to cause disruption. Yesterday we had an incident where a flag was placed courtside.
"The ban is effective immediately. We will continue to work with the players and our fans to ensure the best possible environment to enjoy the tennis."
Russian and Belarusian players were banned from Wimbledon last year but are able to compete as individual athletes without national affiliation at the Australian Open.
Belarus is being used as a key staging ground for Russia's war in Ukraine, which Moscow terms a "special operation".
Their flags are not displayed beside their names in TV broadcasts, as is the case for other players, and their nation is not indicated on draw sheets.