The International Tennis Federation says two umpires have been banned for corruption offenses and four more are suspended.
The sanctions were concealed until being confirmed by the governing body in response to a story Tuesday in The Guardian.
The ITF says Kazakhstani Kirill Parfenov was banned for life in February 2015 for using Facebook to contact another official in an "attempt to manipulate the scoring of matches."
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 didn't give any details on the matches or why four other officials were suspended while under investigation.