Australian Open organisers banned Russian and Belarusian flags from Tuesday at the Melbourne Park after Ukraine's ambassador demanded action when they were sighted among the crowd during Day 1 of the tournament.
The red, white and blue strips of Russia were seen on Monday during the first-round clash between Ukraine's Kateryna Baindl and Russia's Kamilla Rakhimova on Monday.
Also read: Rafael Nadal starts Australian Open title defense with win against Jack Draper
Also, during Danill Medvedev's clash with American Marcos Giron, a Russian flag was unfurled on the Rod Laver Arena.
Notably, since Russia's invasion of Ukraine, Russian and Belarusian players have been competing under a neutral flag as independents.