Red-hot Australian Open favourite Novak Djokovic's father has posed with supporters of Russian president Vladimir Putin outside Melbourne Park.
A group of fans, including a man holding a Russian flag with Putin's face on it, gathered on stairs outside the grand slam complex on Wednesday.
In a video posted to YouTube on Thursday, Srdjan Djokovic was filmed with the pro-Russian spectators, briefly speaking to the camera in Serbian before he walked off.
It comes after Tennis Australia banned spectators from carrying and displaying Russian and Belarusian banners in Melbourne Park on the second day of the tournament.
"A small group of people displayed inappropriate flags and symbols and threatened security guards following a match on Wednesday night and were evicted," a Tennis Australia statement read.
"One patron is now assisting police with unrelated matters.
"Players and their teams have been briefed and reminded of the event policy regarding flags and symbols and to avoid any situation that has the potential to disrupt.
"We continue to work closely with event security and law enforcement agencies."
After Djokovic demolished Russian Andrey Rublev in straight sets to cruise through to his 10th Australian Open semifinal, fans chanted "Russia, Serbia".
Among them was the man who held up the flag featuring Putin, while wearing a T-shirt bearing the pro-war in Ukraine 'Z' symbol.
A different man had earlier been pictured with a 'Z' symbol T-shirt inside Rod Laver Arena during the match.
Past and present Russian flags, the Russian Eagle flag, Belarusian flags and items of clothing with the 'Z' symbol are prohibited items at Melbourne Park.
Four people in the crowd revealed inappropriate flags and symbols and Victoria Police continue to question them, TA said.
TA had initially permitted spectators to bring Russian and Belarusian banners to Melbourne Park, as long as they did not cause disruption, but the policy was quickly reversed.
That rule has been flouted on multiple occasions but Wednesday night's incident was clearly the most blatant.
Russian and Belarusian players, including Rublev, fellow Russian Karen Khachanov and Belarusian women's semi-finalists Aryna Sabalenka and Victoria Azarenka, are allowed to compete in Melbourne, but must do so under a neutral banner.
They were banned by the All England club from participating at Wimbledon last year in reaction to Russia's ongoing invasion of Ukraine.
Russia is Belarus' largest and most important economic and political partner.