There were 246 alerts of suspicious betting on matches in 2015, including three at Grand Slams, the head of the Tennis Integrity Unit has told MPs.
Nigel Willerton described the increase from 91 in 2014 - and just 14 two years earlier - as "obviously concerning".
He also said he had not seen a list of 16 players flagged as suspicious.
Tennis authorities are conducting an independent anti-corruption review after a BBC/BuzzFeed News investigation into suspected illegal betting.
The investigation found that the 16 players, who have all ranked in the top 50, were repeatedly flagged to the Tennis Integrity Unit (TIU) over suspicions they have thrown matches, but were allowed to continue competing.