Singapore: Serena Williams said Thursday that she and her sister Venus have received a written apology from the head of the Russian tennis federation after he caused a storm by calling them the "Williams brothers".

Venus and Serena Williams
Venus and Serena Williams 

Reaching out
Williams said Shamil Tarpischev, who has been fined $25,000 and banned for a year by the Women's Tennis Association over the remarks he made on a TV chat show, had "reached out" over the controversy.

"He has reached out to apologise to both myself and my sister," she said at the WTA Finals in Singapore, after her 6-1, 6-1 win over Eugenie Bouchard.

"It was written. No, I did not speak to him." Williams had earlier slammed Tarpischev's comments, which also earned a strongly worded rebuke from WTA chief Stacey Allaster and condemnation from Russia's world number two Maria Sharapova.

"His comments, I thought, were very insensitive, I thought they were extremely sexist as well as racist at the same time, and I thought they were in a way bullying," Williams said on Sunday.