The Russian flag could be seen in a match between Kamilla Rakhimova and Kateryna Baindl in the first round of the Australian Open in Melbourne today ©Twitter

Ukraine's Ambassador to Australia and New Zealand Vasyl Myroshnychenko has called upon Tennis Australia to enforce its neutrality rule after a Russian flag was spotted in the match between Kamilla Rakhimova and Kateryna Baindl.

The Russian-born Rakhimova is allowed to compete neutrally at the tennis tournament and does not have a flag attached to her on match graphics.

All Russian and Belarusian players are not permitted to formally represent their countries due to International Tennis Federation (ITF) sanctions due to their nations' involvement in the invasion of Ukraine.

The ITF is one of few International Federations who allow athletes from the countries to compete, with the International Olympic Committee's recommendations from February 28 being much harsher - calling for an indefinite ban of all officials and athletes from the country.

Myroshnychenko said he "strongly condemned" the display by a spectator in the women's singles first round match, which Baindl went on to win 7-5, 6-7, 6-1.

"I strongly condemn the public display of the Russian flag during the game of the Ukrainian tennis player Kateryna Baindl at the Australian Open today," Myroshnychenko wrote on Twitter.

"I call on Tennis Australia to immediately enforce its 'neutral flag' policy."

Myroshnychenko previously expressed his opposition to the players being able to compete neutrally at the Australian Open, which was confirmed in October.

Only the Lawn Tennis Association and All-England Lawn Tennis Club, who organise Wimbledon, chose not to invite athletes from the countries.

This led to fines from the Association of Tennis Professionals and Women's Tennis Association and the withdrawal of important ranking points at the tournament.