Venus Williams of the US hits a return against Switzerland's Stefanie Voegele during their Australian Open second round match, in Melbourne, on January 18, 2017 (AFP Photo/SAEED KHAN)

Melbourne (AFP) - US broadcaster ESPN has dropped commentator Doug Adler after he compared Venus Williams to a "gorilla" at the Australian Open -- although he insisted the word he used was "guerrilla".

ESPN said Adler should have been more careful during his coverage of the seven-time Grand Slam-winner's win over Stefanie Voegele.

"During an Australian Open stream on ESPN3, Doug Adler should have been more careful in his word selection," an ESPN statement said.

"He apologised and we have removed him from his remaining assignments."

During the second-round match on Wednesday, Adler, a 59-year-old former player, said: "She (Voegele) misses a first serve and Venus is all over her.

"You see Venus move in and put the gorilla effect on. Charging."

Viewers were quick to register their distaste on social media, while tennis journalist Ben Rothenberg called it "appalling stuff".

"Horrifying that the Williams sisters remained subjected to it still in 2017," he tweeted.

A report on the ESPN website said: "Because the words gorilla and guerrilla are pronounced similarly, it's impossible to say for certain which word Adler spoke."

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