Two tennis umpires have been banned and four others are under investigation for corruption, authorities said Tuesday.
The sanctions were confirmed by the International Tennis Federation in response to a story published online by The Guardian.
Kirill Parfenov of Kazakhstan was banned for life in February 2015 for using Facebook to contact another official in an "attempt to manipulate the scoring of matches," the ITF said in a statement.
Denis Pitner of Croatia was suspended for a year in August after passing on details on the "physical well-being of a player to a coach during a tournament and regularly logging on to a betting account from which bets were placed on tennis matches," the ITF said.
Four other unidentified officials were suspended while investigations continue into their conduct.
"In order to ensure no prejudice of any future hearing we cannot publicly disclose the nature or detail of those investigations," the ITF said. "Should any official be found guilty of an offense, it will be announced publicly."
The ITF code was changed in December to allow the public reporting of sanctions for officials, but the governing body could not explain why it only announced details following media questions. The ITF also declined to explain why it would not provide details on matches involved in the case.
The Guardian said the offenses took place on the Futures Tour, the lowest rung of professional tennis. It said umpires allegedly took bribes from betting syndicates in exchange for manipulating live scores, allowing gamblers to place bets already knowing the outcome of the next point.
The story follows BBC and BuzzFeed allegations about match-fixing at the top level of the sport that overshadowed the start of the Australian Open last month. Those reports led to the announcement of an independent review into tennis' anti-corruption practices, which are overseen by the Tennis Integrity Unit.