Novak Djokovic’s father has been warned about his future behaviour after causing outrage at the Australian Open by posing with a Russian flag that had Vladimir Putin’s face on it.

Tournament officials were forced to issue a statement after a video emerged on a pro-Russia YouTube channel showing the reckless actions of the Serbian star’s controversial parent.

Soon after Djokovic reached the semi-finals on Thursday night his father mingled with fans declaring their support for Russia, with police and Tennis Australia confirming that four spectators were evicted from Melbourne Park.

Australian Open entry regulations expressly forbid any flags in support of Russia or Belarus.

A video posted on YouTube shows Srdan posing alongside the flag and a sympathiser who shouts ‘Long Live Russia!’. 

Djokovic Senior is shown being warmly greeted by his son’s fans and he appears to say something supportive before moving on.

Srdan was particularly outspoken last year when his son was deported after being detained as a result of not being vaccinated, accusing the Australian state of trying to ‘assassinate’ his superstar offspring.

The player himself has desperately tried to avoid controversy since arriving in Australia to focus on his title efforts as he prepares to meet American Tommy Paul in the semi-final on Friday. 

Unwittingly or not, on Wednesday he could be seen signing something for a man who had earlier been wearing a ‘Z’ T-shirt - Z having become the makeshift logo of the Russian invaders of Ukraine.

This led embarrassed Tennis Australia to issue a general warning at a tournament where players from the aggressor nations are still left in.

‘A small group of people displayed inappropriate flags and symbols and threatened security guards following a match on Wednesday night and were evicted,’ it 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,' read the statement.

Entirely separately on a pure tennis level, there has been speculation about how serious is a hamstring injury that he has been carrying while progressing through the tournament.

A faction of Serbian fans at Melbourne Park have been keen to demonstrate their kinship for Russia, in spite of the massive human cost of the Ukraine invasion on both sides. 

Attempts to stop them public displaying support for Putin at the tennis have not been successful, judging by Wednesday night.

Ukrainian ambassador Vasyl Myroshnychenko expressed his disgust at their behaviour today.

‘It’s a full package. Among the Serbian flags there is a Russian flag, Putin, Z-symbol, so called Donetsk People Republic flag. It’s such a disgrace,' he told the Herald Sun.