Novak Djokovic’s father decided to stay away from the 21-time Grand Slam champion’s semifinal after getting embroiled in a flap involving spectators who brought banned Russian flags to Melbourne Park, Tennis Australia said Friday.

In a release e-mailed to reporters about 2 1/2 hours before Djokovic was scheduled to face Tommy Paul for a berth in the men’s singles final, tournament organizers said Srdjan Djokovic “has issued a statement confirming that he will not attend” the match.

“Throughout the event, we’ve spoken with players and their teams about the importance of not engaging in any activity that causes distress or disruption,” Tennis Australia said.

“We will continue to strive for the safety of fans at the event and reiterate our position banning flags from Belarus and Russia,” the group added. “Tennis Australia stands with the call for peace and an end to war and violent conflict in Ukraine.”

After the younger Djokovic’s quarterfinal victory over Russian player Andrey Rublev on Wednesday, Srdjan Djokovic was filmed standing with a group of people waving Russian flags — at least one showing an image of Vladimir Putin — outside Rod Laver Arena.

Four people were kicked out of the tournament because of the flags and for threatening security guards that night, police and Tennis Australia said.

On Jan. 17, the second day of the Australian Open, flags from Russia and Belarus were banned from Melbourne Park after more than one was brought into the stands by spectators the day before.

Normally, flags can be displayed during matches at Melbourne Park. But Tennis Australia reversed that policy for the two countries involved in the invasion of Ukraine that began nearly a year ago, saying the flags were causing disruption.

Athletes from Russia and Belarus were barred last year from competing in various sports events, including the men’s World Cup in soccer and Wimbledon, the Billie Jean King Cup and Davis Cup in tennis, because of the war in Ukraine. Russia invaded, with help from Belarus, in February.

Russian and Belarusian players have been allowed to play at the Australian Open, French Open and U.S. Open, but as “neutral” athletes, so their nationalities are not acknowledged on any official schedules or results for the event and their countries’ flags are not displayed on TV graphics.