The number of suspicious betting patterns in tennis is on the rise and is a "concern", says the first annual report published by the Tennis Integrity Unit (TIU).
In 2016, nine players and officials were sanctioned as a result of TIU disciplinary investigations.
There were 292 alerts to the TIU last year, with eight of them from Grand Slam, ATP and WTA matches.
In 2015 there were 246 alerts to the TIU.
The TIU said alerts are not proof of corruption, but that all cases have to be investigated.
It added it will continue to review its systems to tackle corruption, "ensuring its provisions and powers are current and relevant".