Russian Tennis Federation president Shamil Tarpischev has been forced to publicly apologise for his slur against the Williams sisters, Serena and Venus.

The International Tennis Federation (ITF) came under fire from Martina Navratilova on Monday for failing to act after Tarpischev described the Williams's as "brothers".

The Womens’ Tennis Association (WTA) responded swiftly to Tarpischev’s remarks by banning him for a year and issuing a fine of $25,000 (€19,500).

Navratilova, however, claimed the ITF’s silence on the matter was “pretty deafening”.

The 59-times Grand Slam champion added: “Certainly this kind of bullying comment cannot be tolerated from anyone, but particularly from a high-up official in the tennis world.”

ITF president Francesco Ricci Bitti, however, has now responded and made it clear to Tarpischev such comments will not be tolerated.

Ricci Bitti believes Tarpischev’s apology and the WTA’s actions are a sufficient punishment.

Speaking to Press Association Sport, Ricci Bitti said: “The ITF was very disappointed when it learned that Shamil Tarpischev, long-time president of the Russian Tennis Federation, made derogatory remarks about the gender of Serena and Venus Williams.

“What Mr Tarpischev said was wholly unacceptable to the ITF and, when we learned of the issue, we encouraged him to apologise immediately.

“Mr Tarpischev has taken an important step by sending his apology to the ITF, the WTA and to the Williams sisters.

“Although Mr Tarpischev assured us his comment was meant as a joke, we made it clear to him what he said is inappropriate in any context.

“We were especially disappointed as Mr Tarpischev has a long and distinguished career in tennis, serving as Davis Cup and Fed Cup captain, and fostering the growth of tennis in Russia, including the development of many successful men and women players.

“We hope his acceptance of fault in this matter, which includes the penalty assessed by the WTA Tour, will allow all of us to move forward.”