The passport details and vaccination certificates of hundreds of professional table tennis players have been leaked online after a security issue on the server of the sport's governing body ITTF, Dutch news service RTL Nieuws reported on Monday.
China's Olympic champion Ma Long and compatriot and world champion Fan Zhendong were among victims of the breach of privacy, with their passport details available online, the report said.
An ITTF spokesperson said it had no evidence that personal information had been accessed prior to the report.
"A security issue on our server was brought to our attention by an independent technology expert. The ITTF secured the access as soon as it became aware," the spokesperson said.
"Documents were stored in this location for only a short period of time, and we have no evidence personal information was accessed prior to the report."
The spokesperson said the global body regretted the incident and was contacting affected member associations.
"Security and data privacy are of the utmost importance for the ITTF," the spokesperson added.
"We have already implemented additional security measures and we will monitor suspicious activities. A thorough security review and an investigation are currently being undertaken."