The president of the Russian Tennis Federation Shamil Tarpischev has been fined $25,000 and banned from the women's tour for a year after referring to Serena and Venus Williams as "the Williams brothers" on a television chat show last week.
Women's Tennis Association (WTA) chief executive Stacy Allaster said the comments were "insulting, demeaning and have absolutely no place on our sport".
Allaster added: "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.
"As a result of his comments I have ordered Mr. Tarpischev to be fined $25,000, the maximum allowed under WTA rules."
She added that he would be suspended from any involvement with the WTA for a year.
World number one Serena Williams has won 18 grand slam singles titles while her sister Venus has won seven majors.
Dave Haggerty, president of the United States Tennis Association, called on Tarpischev to issue an apology.
"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," Haggerty said in a statement.
"Unfortunately, his comments do not embody either of these traits and in fact were reprehensible."
