WATCH | Novak Djokovic's father filmed with fans holding pro-Russia flags at Australian Open

Novak Djokovic's father has been filmed posing with fans brandishing pro-Russian flags at the Australian Open in scenes Ukraine's ambassador on Thursday slammed as "a disgrace".

LIVE UPDATES from the Australian Open

The Serbian star had just booked his place in the tournament semi-final with a straight sets thumping of Russian opponent Andrey Rublev in Rod Laver Arena on Wednesday night.

After the match a group of fans unfurled Russian flags near the stadium, including one featuring Vladimir Putin's face, chanting pro-Russian slogans.

Tennis Australia said four people "revealed inappropriate flags and symbols and threatened security guards". Police were called and they were ejected from Melbourne Park.

A video later posted to a pro-Russian Australian YouTube account showed Djokovic's father Srdjan posing with a man holding the Putin flag.

It was captioned: "Novak Djokovic's father makes bold political statement."

This is…quite a mess for the #AusOpen, to say the least.Srdjan Djokovic posing with the pro-Putin rally last night just outside Rod Laver Arena.The levels of security breakdowns that allowed for this are staggering.Story/video via @jamesgraysport:https://t.co/L4gtaKKNP6 pic.twitter.com/qnOx3MGYqB

Serbian tennis reporters confirmed it was Djokovic's father and the Melbourne Age newspaper reported he said in Serbian: "Long live Russia."

Spectators are banned from having Russian or Belarusian flags at the Grand Slam after Ukraine's ambassador to Australia and New Zealand, Vasyl Myroshnychenko, demanded action when they were seen among the crowd last week.

He said on Twitter on Thursday that the latest incident was shameful.

"It's a full package. Among the Serbian flags, there is: a Russian flag, Putin, Z-symbol, so-called