Two professional tennis umpires have been banned and four more are under investigation for fixing games to assist betting syndicates, it has emerged.
Kazakhstan's Kirill Parfenov was banned for life last February for contacting another official on Facebook in an attempt to manipulate the scoring of matches.
And Croatian Denis Pitner was suspended for 12 months after sending information about a player to a coach during a tournament and logging onto a betting account from which wagers were placed on games.
The revelations come as professional tennis faces increasing scrutiny over allegations of corruption within its highest levels.
It is already reeling from reports last month that 16 players who have been ranked in the top 50 had been repeatedly flagged to the Tennis Integrity Unit over concerns they had thrown matches.
Tennis authorities rejected accusations that evidence of match-fixing had been suppressed or had not been properly investigated over the past decade.
But the spectre of match umpires possibly colluding with betting syndicates by manipulating live scoring data at low-ranking events is a further blow to the sport's image.
In 2014 French tennis official Morgan Lamri was banned for multiple breaches of the Tennis Anti-Corruption Programme.
Explaining why the latest suspensions had only just been disclosed, The International Tennis Federation (ITF) said its Code of Conduct for Officials did not require it to name those sanctioned until it tweaked the code at the start of the year.
The ITF would not comment on reports that said umpires from Kazakhstan, Turkey and Ukraine were among those being investigated.
However, it did address suggestions that a five-year deal worth a reported $70 million with data company Sportradar had inadvertently exposed tennis to corruption.
Sportradar passes on scoring data from umpires, even at bottom rung Futures circuit tournaments, to 'in-play' betting websites around the world.
By deliberately delaying inputting the outcome of a point, umpires can help court-side gamblers to place bets knowing what was going to happen next.
'The ITF's data contract with Sportradar for an official data feed provides regulation and control where previously there was none,' a statement said.
'Our agreement with Sportradar, like those in place with ATP and WTA, by creating official, accurate and immediate data, acts as a deterrent to efforts by anyone trying to conduct illegal sports betting and/or unauthorised use of data for non-legal purposes.
'Sportradar are excellent partners and share with the ITF the goal of ensuring the integrity of our sport.'
In the wake of revelations some 16 players in the top 50 were suspected of match fixing, Roger Federer (left) said they should be named, while Novak Djokovic (right) revealed he had once rejected an offer to throw a match for money
Tennis is one of the most gambled on sports in the world, with bookmakers actively taking bets mid-match.
Like cricket, match-fixing does not necessarily mean throwing a match, but could involve taking money just to double fault or lost a set.
Last month the sport was rocked by reports 16 players who have ranked in the top 50 are among those to be suspected of match fixing.
Incredibly, eight of those 16, including one Grand Slam winner, were alleged to have been playing at the Australian Open.
In the wake of the accusations, tennis legend John McEnroe admitted many had heard 'stories about this going on at the low levels', but added that 'no one knew it was happening at the Grand Slams'.
Many were also shocked to learn that some of the sport's top players had been approached and offered big money to throw matches.
Djokovic confirmed last month he was offered money to intentionally throw a match. The 10-time Grand Slam champion said that he was not directly approached but members of his support team were offered the money in Russia in 2007, an offer the player said was immediately rejected.
