The Herald Sun has backed its veteran cartoonist, Mark Knight, insisting his recent portrayal of Serena Williams had nothing to do with race or gender.

Mr Knight’s depiction of the 23-time Grand Slam champion after the controversial US Open in the Australian paper last weekend, featured her with a larger figure and exaggerated lips and nose, resembling racist portrayals of black people during the Jim Crow era in the US.

It also depicted Ms Williams stomping on a smashed racket with a pacifier nearby – a representation criticised for perpetuating the trope of an “angry black woman”.

The backlash to Mr Knight’s cartoon was swift; many have taken to social media to lambast the cartoonist for his depiction of Ms Williams.

Harry Potter author J.K Rowling called the drawing both “racist” and “sexist” in a post published to Twitter on Monday.

“Well done on reducing one of the greatest sportswomen alive to racist and sexist tropes and turning a second great sportswoman into a faceless prop,” she wrote.

Mr Knight has since responded to the widespread criticism, insisting that the cartoon was about Ms Williams’ “behaviour”.

“I drew this cartoon Sunday night after seeing the US Open final, and seeing the world’s best tennis player have a tantrum and thought that was interesting,” he said. “The cartoon about Serena is about her poor behaviour on the day, not about race. The world has just gone crazy.”

Sun editor Damon Johnston backed Mr Knight, also charging Ms Williams had a “tantrum” at the US Open.

“A champion tennis player had a mega tantrum on the world stage, and Mark’s cartoon depicted that,” Mr Johnston said. “It had nothing to do with gender or race. this was about a bad sport being mocked.”

Serena Williams says she is sticking up for women's rights following a heated Umpire Exchange at the US Open

The US Open ended with Naomi Osaka winning over Ms Williams, who got in a scoring dispute with the umpire Carlos Ramos. Mr Ramos issued three penalties to Ms Williams during the match.

After issuing a penalty for receiving coaching from the sidelines – which Ms Williams immediately denied and insisted the umpire apologise for the insinuation that she cheated – Mr Ramos imposed a penalty after she slammed her racket in frustration in the midst of the game.

He then ultimately penalised her for an entire game, accusing her of verbal abuse, after she called him a “thief” while calling out sexist double standards in tennis.

Tennis legend Billie Jean King defended Ms Williams in an op-ed for The Washington Post, agreeing that men are treated differently than women – especially women of colour – in tennis and “most arenas of life.”

“Did Ramos treat Williams differently than male players have been treated?” King wrote. “I think he did. Women are treated differently in most arenas of life. This is especially true for women of colour. And what played out on the court yesterday happens far too often.”

A number of celebrities have taken to social media to share similar sentiments to Ms King, arguing that Ms Williams had been punished for defending herself. The tennis star has since been fined $17,000 [£13,000] for three code violations during the match.

The US National Association of Black Journalists released a statement calling the Sun’s cartoon “repugnant on many levels”.

“The [10 September] cartoon not only exudes racist, sexist caricatures of both women, but Williams’ depiction is unnecessarily sambo-like,” the statement read.

The US journalism organisation also criticised Mr Knight’s portrayal of Ms Osaka, saying the cartoon “grossly inaccurately depicts two women of colour”.

Ms Osaka, who is both Haitian and Japanese, is depicted as a woman with fair skin and blonde hair standing next to an umpire who is asking: “Can you just let her win?”

Serena Williams vs Naomi Osaka: Story of the US Open women's final Show all 8 1 /8 Serena Williams vs Naomi Osaka: Story of the US Open women's final Serena Williams vs Naomi Osaka: Story of the US Open women's final Serena gets headed Serena Williams was aiming for her seventh US Open title against Naomi Osaka, but things did not go her way. Reuters / USA TODAY Sports Serena Williams vs Naomi Osaka: Story of the US Open women's final Naomi Osaka wins first set The 20-year-old from Japan won the first set 6-2, but there was drama ahead Getty Serena Williams vs Naomi Osaka: Story of the US Open women's final First the coach Williams was penalised for what the umpire deemed to be coaching from the sidelines by Partrick Mouratoglou. She disagreed and the war with the official began by Williams saying she was not a cheat. “I don’t cheat to win,” Williams told Ramos after he had issued the code violation. “I’d rather lose.” Getty Serena Williams vs Naomi Osaka: Story of the US Open women's final Then the racket Williams took her anger out on her racket after dropping a serve, the penalty was a point deduction. “You owe me an apology. I have never cheated in my life," she told the umpire. "I have a daughter and I stand for what is right.” USA TODAY Sports Serena Williams vs Naomi Osaka: Story of the US Open women's final And finally, the tournament referee A furious Williams received a third code violation for verbal abuse and demanded to see the tournament referee, Brian Early. An increasingly upset Williams told Earley that male players say far worse without receiving similar punishment and said she was being penalised “because I’m a woman”. AP Serena Williams vs Naomi Osaka: Story of the US Open women's final Naomi Osaka wins 6-2 6-4 Naomi Osaka won her first Grand Slam, but the match will be remembered for a completely different reason. Getty Serena Williams vs Naomi Osaka: Story of the US Open women's final Williams priases Osaka Williams was hesitant to do her on-court interview but praised Osaka's performance. "I don't wanna be rude or interrupt or do questions. I wanna say she played well, it's her first Grand Slam. I know the guys were rooting and I was rooting too." Getty Serena Williams vs Naomi Osaka: Story of the US Open women's final Williams calls for fairness "But I've seen other men call other umpires several things. I'm here fighting for women's rights and for women's equality and for all kinds of stuff. For me to say 'thief' and for him to take a game, it made me feel like it was a sexist remark. He's never taken a game from a man because they said 'thief'. It blows my mind," she said. "I just feel like the fact that I have to go through this is just an example for the next person that has emotions, and that wants to express themselves, and wants to be a strong woman. Getty

People on social media have lambasted Mr Knight for erasing Ms Osaka’s blackness.

“A cartoon in The Herald Sun … depicts Serena Williams as a giant baby with a huge nose and lips, and Naomi Osaka as a blonde white girl,” one Twitter user wrote.

Mr Knight apparently addressed his depiction of Ms Osaka saying “people are making up stuff that is just not true,” HuffPost reported.

“I depicted her as I saw her in photographs at the US Open,” he added.

Michael Miller, executive chairman of News Corp Australasia, called the widespread international backlash an effect of too much “PC” or political correctness.

“Poor behaviour in any sport needs to be called out,” he wrote on Twitter.

Ms Williams, and her body, has been under constant scrutiny throughout her career. In an interview with Harper’s Bazaar earlier this year, she addressed overcoming the attacks she has received for having a muscular physique.

“I can show Olympia [her daughter] that I struggled, but now I'm happy with who I am and what I am and what I look like,” she said. “Olympia was born and she had my arms, and instead of being sad and fearful about what people would say about her, I was just so happy.“

Mr Knight had been previously criticised for cartoon he drew last month, sparking condemnation for depicting black teenagers rioting and trashing a train station.

Rohan Leppert, a councillor in Melbourne, called Mr Knight’s August cartoon “utterly shameful”.