A member of French player Aravane Rezai's family has been banned from WTA events and is under investigation because of a "serious safety matter" affecting her "health and well being", the tour said on Sunday.
Rezai, who was seeded 17th, went out 6-0 3-6 7-5 to Czech Barbora Zahlavova Strycova in the first round of the Australian Open last week.
"The health and well being of our players is the number one priority for the WTA," a statement said.
"A serious safety matter has been brought to the WTA's attention, which has resulted in a family member of Aravane Rezai being indefinitely suspended from all future WTA events pending our investigation."
The 23-year-old Rezai had her breakthrough year in 2010, winning titles in Madrid and Bastad and ending the year in the top 20 in the world for the first time.
"In respect of the privacy of the player involved, the WTA is not in a position to comment further on the details of the matter," the statement added.