Last updated on .From the section Tennis

Last month, the BBC and Buzzfeed exposed evidence of widespread suspected match-fixing in tennis

Two umpires have been banned by the International Tennis Federation and four more are being investigated over allegations of fixing.

The ITF has revealed it barred Kazakhstani Kirill Parfenov for life in February 2015 and suspended Croatia's Denis Pitner for a year last August.

Four others are being investigated for allegedly taking bribes to manipulate scores on the Futures Tour.

This follows BBC and BuzzFeed claims of match-fixing in tennis.

That joint investigation uncovered files showing that, over the past 10 years, 16 high-ranking players have been repeatedly flagged to the Tennis Integrity Unit (TIU) over suspicions they have thrown matches.

It led to the announcement of an independent review into tennis' anti-corruption practices.

In a joint statement, the TIU and ITF said: "Kirill Parfenov of Kazakhstan was decertified for life in February 2015 for contacting another official on Facebook in an attempt to manipulate the scoring of matches.

"Separately, Denis Pitner of Croatia had his certification suspended on 1 August 2015 for 12 months for sending information 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."

ATP president Chris Kermode tells the BBC he is aware there is match-fixing within tennis but says it is at an 'incredibly small level'

What is 'courtsiding'?

The Guardian, whose investigation brought the latest suspensions to light, external-link says the umpires involved on the Futures Tour, the lowest rung of professional tennis, are, in effect, accused of an act known as 'courtsiding'.

It is a practice whereby gamblers attend sporting events live and bet on scores before bookmakers have up-to-date information.

Umpires at smaller tournaments update the scoreboard themselves after each point, and this information is transmitted to live-score sites and bookmakers.

The umpires being investigated are alleged to have deliberately delayed updating the scores for up to 60 seconds - allowing gamblers to place bets on events they knew the outcome of.

All four have been suspended until investigations are complete.

The Guardian also says some umpires are alleged to have sent text messages to gamblers before updating the score on their tablet computer.