World number two Naomi Osaka has been fined $15,000 for not attending a media press conference after her first-round win in the French Open.
The 23-yer-old Japanese native beat Romania's Patricia Maria Tig in straight sets on Sunday to progress to the second round at Roland Garros.
As well as the fine, she also faces expulsion from the Grand Slam competition if she continues to refuse to speak to the media, organisers have said.
Osaka said last week she will not participate in any news conferences during the tournament because she wants to protect her mental health.
A joint statement from the four Grand Slam organisers said Osaka also faces "more substantial fines and future Grand Slam suspensions".
Part of Sunday's statement read:
"We have advised Naomi Osaka that should she continue to ignore her media obligations during the tournament, she would be exposing herself to possible further Code of Conduct infringement consequences.
"As might be expected, repeat violations attract tougher sanctions including default from the tournament (Code of Conduct article III T.) and the trigger of a major offence investigation that could lead to more substantial fines and future Grand Slam suspensions (Code of Conduct article IV A.3.).
"We want to underline that rules are in place to ensure all players are treated exactly the same, no matter their stature, beliefs or achievement.
"As a sport there is nothing more important than ensuring no player has an unfair advantage over another, which unfortunately is the case in this situation if one player refuses to dedicate time to participate in media commitments while the others all honour their commitments.
"Finally, all Grand Slams remain committed to continually reviewing and discussing opportunities, together with the Tours and the players, to improve every aspect of the player experience, including with the media.
"But we consider this is only ever achieved through respectful and constructive discussions. "