Novak Djokovic's father Srdjan has been filmed posing for pictures with supporters of Russia president Vladimir Putin at the Australian Open.
Srdjan Djokovic was pictured with a man who was holding a Russian flag carrying Putin's face, and wearing a T-shirt printed with the pro-war Z symbol.
Russian and Belarusian flags and symbols have been banned at Melbourne Park since a Russian flag was displayed during a match between Ukraine's Kateryna Baindl and Russia's Kamilla Rakhimova on the opening day.
There was a show of support for Putin after Djokovic's quarter-final win over Russian Andrey Rublev on Wednesday evening.
A Russian flag bearing Putin's image was displayed outside the Rod Laver Arena by a group of fans wearing Serb colours. Chanting support for Russia, some had Serbia's flag wrapped around their shoulders.
In a statement, Tennis Australia said: "A small group of people displayed inappropriate flags and symbols and threatened security guards following a match on Wednesday night and were evicted.
"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."
In 2022, Russian and Belarusian were players were banned from competing at Wimbledon because of the invasion of Ukraine.
Thursday's women's semi-finals feature two Belarusian players in Victoria Azarenka and Aryna Sabalenka who could yet meet in the final.
On Friday, Russia's Karen Khachanov plays in the men's semi-finals, although all three are compelled to compete under a neutral flag.
Djokovic's representatives have been approached for comment.