Martina Navratilova has called for tougher punishment for Australian Nick Kyrgios after the "insulting remark" he made to Stan Wawrinka.
The 20-year-old was fined £6,400 after making a lewd suggestion about Wawrinka's girlfriend in a Rogers Cup match. He later apologised.
The ATP has also served Kyrgios with a 'notice of investigation'.
Navratilova, an 18-time grand slam champion, tweeted: "There needs to be more than a fine."
She added: "There is no place for that behaviour."
The ATP may yet suspend Kyrgios from its events.
Stacey Allaster, chairman and chief executive of the WTA, said: "The statement made by Nick Kyrgios is crude and unacceptable.