Match-fixing fears return after flood of 'unusual' bets

Fears over match-fixing in men's tennis have surfaced for the third time in a month after "extreme movements" in betting patterns on a match between two top 100 players led to cancellation of markets and reports to the authorities.

A flood of "unusual" money was placed on Spain's Oscar Hernandez, the world No 56, to beat Serbia's Janko Tipsarevic, the world No 79, in straight sets in the first round of the Mercedes Cup in Stuttgart on Tuesday.

High street firms including William Hill suspended betting, while Betfair reported "extreme movements" as abnormal sums were matched on Hernandez. The Spaniard won 6-4, 6-4.

The match has been referred to the Gambling Commission and to the sport's in-house Tennis Integrity Unit for investigation. The case is at least the sixth in men's tennis in 2009 to be referred to the GC, the TIU or both.

The last was a first-round Wimbledon match between America's Wayne Odesnik and Jürgen Melzer, which Melzer won in straight sets after hundreds of thousands of pounds had been placed on that scoreline.

The week before, the TIU opened an investigation into a match at the Ordina Open in the Netherlands, where "unusual" bets on Hernandez to beat Austria's Daniel Koellerer led to the suspension of betting. Hernandez won that match.

Two matches earlier in the year featuring losses for different Argentinian players are also understood to have been flagged up as "of concern" while there is on ongoing investigation into a first-round match in April at the Monte Carlo Masters, where France's Jean-René Lisnard beat Belgium's Christophe Rochus, 6-2, 6-2, after "substantial and unusual" bets on that outcome.

The authorities' first line of inquiry in such cases is whether "insider information" has allowed someone close to a player to profit, from knowledge about an injury for example. No player has been accused of breaking the rules of tennis at this stage.

Trade in such information is banned in tennis. Bookmakers tend to be more relaxed about it. Often bookies will not even report "unusual" betting where an injury offers an explanation.

In other cases, bookmakers withhold payment on bets while the authorities try to rule out premeditated fixing. For example, a spokesman for William Hill said yesterday: "We won't pay out on Lisnard v Rochus until the Gambling Commission has cleared it."

The Gambling Commission refuses to discuss any cases. The TIU operates in similar secrecy, replying yesterday to a series of questions with: "No comment."