An Australian cartoonist has defended his depiction of Serena Williams at the US Open, after the image went viral and was criticised as racist and sexist, according to the BBC.

Mark Knight's newspaper cartoon showed Williams jumping above a broken racquet next to a baby's dummy. Critics said it used racist stereotypes.

The cartoonist denied it was racist, saying he had intended to depict only the tennis player's "poor behaviour".

Some also said Knight had "whitewashed" Japanese player Naomi Osaka.

Williams sparked controversy during her loss to Osaka, whose father is Haitian and mother Japanese, when she accused the umpire of sexism and being a "thief".

Knight's drawing was published in Australia's most-read newspaper, the Herald Sun on Monday, and referenced Williams's outburst and showed the umpire asking Osaka: "Can you just let her win?"

It has been strongly defended by Knight and the newspaper's editor, Damon Johnston, who denied the cartoon is racist or sexist.

"It rightly mocks poor behaviour by a tennis legend... Mark has the full support of everyone," he said in a tweet.

Critics, including author JK Rowling, compared the cartoon of Williams to past racist caricatures of African-American people.

"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."

Another critic said:

"You couldn’t be more racist if you tried - and you reeeeeaaally tried. Using those classic sambo tropes- enlarged lips, overexaggerated body parts to depict Serena as hyper masculine- next time just use an old ad from the 1800s- no one would notice the difference in your racism"

Others on social media pointed out that Osaka, who is mixed race, had been drawn as a white woman with blonde hair.

The National Association of Black Journalists in the US denounced the cartoon as "repugnant on many levels".

"[It] not only exudes racist, sexist caricatures of both women, but Williams' depiction is unnecessarily sambo-like," it said in a statement.

The 1899 children's book, The Story of Little Black Sambo, featured derogatory racial depictions - such as characters with thick red lips.

Knight said he had "no knowledge of those cartoons or that period", saying on Tuesday that "the world has just gone crazy".

"The cartoon was just about Serena on the day having a tantrum. That's basically it," he told the Australian Broadcasting Corporation.

Knight also rejected a suggestion that he would not draw a similar image of a man. As evidence, he tweeted his recent cartoon of tennis player Nick Kyrgios.

By 12:15 GMT on Tuesday, both his Twitter and Facebook accounts had been shut down.

You can see the cartoon here: http://www.todaysecho.com/man-who-drew-serena-williams-cartoon-accused-of-racism/