"The statements made by Shamil Tarpischev on Russian television with respect to two of the greatest athletes in the history of women's tennis are insulting, demeaning and have absolutely no place in our sport," she said. 

"The WTA was founded on principles of equality, opportunity and respect and Venus and Serena embody all of these attributes.

"Mr Tarpischev's statements questioning their genders tarnish our great game and two of our champions.

"His derogatory remarks deserve to be condemned and he will be sanctioned."

The WTA also called for Tarpischev - who is the chairman of the Board for the Kremlin Cup tournament currently being held in Moscow -  to issue a personal apology to the Williams sisters, who between them have won 25 singles Grand Slam titles. 

Shamil Tarpischev made his comments questioning the sexuality of the Williams sisters on Russian television show "Evening Urgant" alongside former WTA player Elena Dementieva ©Twitter

The United States Tennis Assocaition (USTA) described his comments as "reprehensible".

"As the President of the USTA and a member of the Board of dDirectors of the International Tennis Federation, I call on Shamil Tarpischev to issue a formal apology to Venus and Serena Williams," said a statement from President Dave Haggerty.

"As the President of the Russian Tennis Federation and a member of the International Olympic Committee, Mr Tarpischev is expected to conduct himself with the highest degree of integrity and sportsmanship.

"Unfortunately, his comments do not embody either of these traits and in fact were reprehensible."

Tarpischev, 66, has been a member of the IOC since 1994 and was this year appointed as member of its Entourage Commission, which deals with matters concerning the relationship between athletes, coaches, managers, sponsors and all other stakeholders that support athletes.

The Williams sisters are among the most successful athletes in Olympic history, having won four gold medals each.

Serena won the women's singles title at London 2012 and collected another gold in the women's doubles, teaming up with Venus to claim the title for the third time in four Olympics. 

Serena and Venus Williams celebrate winning the women's doubles at London 2012, the fourth Olympic gold medal for each player ©Getty Images

insidetehgames has contacted the IOC to see if they plan to take any action themselves against Tarpischev, a special advisor on sport to Russian President Vladimir Putin, but has yet to receive a response.

Tarpischev, President of the Russian Tennis Federation since 2002, made his comment on the Russian late-night show "Evening Urgant" alongside former WTA player Elena Dementieva last week.

When Dementieva was asked what it was like to play against the Williams sisters, Tarpischev jumped in and referred to them as the "Williams brothers".

Tarpischev added later in the inreview: "It's frightening when you look at them.

"But really you just need to play against the ball."

The $25,000 (£15,500/€20,000) fine is the maximum allowed under WTA Tour rules.

But the punishment has been criticised by Russia's Sports Minister Vitaly Mutko.

"The WTA decision to ban him is upsetting," he said.

"Tarpishchev is an authority in the world of tennis.

"And I'm very sorry about this incident.

"But we also need to understand whether his words were interpreted correctly and possibly to try to mitigate the WTA verdict."

Shamil Tarpischev has been a member of the IOC since 1994 and sits on its Entourage Commission, which is supposed to protect the interests of the athletes ©Getty Images

Tarpishchev later released a statement which fell short of an apology, claiming his comments had been taken out of context - he said the show he was speaking on was "humourous".

He said: "I didn't want to offend any athlete with my words. 

"I regret that this joke...has garnered so much attention.

"I don't think this incident deserves so much fuss."

Tarpischev added that the Williams sisters are "outstanding athletes" who "personify strength and perseverance". 

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