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Taking a dive in boxing or knobbling a horse in racing are as old as the sports themselves. Even team sports - such as baseball, football and cricket - have long been afflicted by match-fixing and dodgy gambling, mostly by influencing money-hungry players.
But sporting corruption has taken a relatively disturbing twist this week in German football: the active involvement of the referee. Robert Hoyzer, a lower-league official, has admitted fixing at least five matches in return for a five-figure sum, alleged to be from a Croatian betting syndicate. At the heart of the scandal - the largest to hit German football since more than 50 players, officials and coaches were caught up in corruption in 1971 - was a cup game in which Bundesliga side Hamburg SV lost a 2-0 lead against lower-placed opposition as Hoyzer awarded two dubious penalties and sent a player off.
Hoyzer's admission, after initially denying the allegations, has sent German football into shock. Hamburg - whose manager had to resign shortly after the cup match as the team's form nosedived - are considering taking legal action. The German football association, the DFB, has been deeply embarrassed by the scandal and is changing the rules so that referees will know only two days before a game which one they will officiate. It is unclear, however, how this measure will stop last-minute betting on games where the official has already been bought.
More serious is the thought that fans and teams will no longer accept a controversial decision as flawed but honest. "We cannot link every questionable decision to what is happening at the moment," said Torsten Frings, a midfielder at Bayern Munich. "That would slowly bring about the death of football."
The scandal has even managed to overshadow the start of ticket sales for what is the biggest sporting event to take place in Germany for three decades - next year's football World Cup. Sepp Blatter, president of the game's world governing body Fifa, told the DFB it and German football were "in the spotlight", criticised how long they took to uncover the matter and added that it all must be swiftly resolved.
Yet for many observers this type of scandal is unlikely to go away without a concerted effort from authorities worldwide in all sports. Match-fixing allegations of one sort or another in football have surfaced in countries such as South Africa, Israel, Italy and Portugal in the last year. However, only some of the cases led to convictions against those involved.
Past evidence shows just how hard it is to crack down on bribery and corruption in sport. Perhaps the most famous example of alleged match-fixing is the 1919 baseball World Series when Chicago White Sox players were suspected of being involved in a betting scam to lose. Although the players were banned by baseball authorities, they were acquitted of the criminal charges. Fans even later pushed for one of those involved, "Shoeless" Joe Jackson, to be inducted into the Hall of Fame.
The case of Bruce Grobbelaar, the former Liverpool goalkeeper accused of match fixing, also highlights the complexity of the issue. After numerous legal battles, Britain's highest court said although it had been proved he took bribes, it could not be shown he fixed matches.
Similarly in cricket, which was rocked by a series of bribery and match-fixing allegations in the 1990s, only a few players were banned and one of those, Ajay Jadeja of India, had his ban overturned in 2003. The International Cricket Council, the governing body, has since taken serious steps to stamp out corruption by bringing in new offences and penalties.
But some worry that as long as some sportsmen are relatively lowly paid - as cricketers are and baseball players were - the risk of corruptibility remains. A trio of university professors recommended in a report on cricket's woes that wages would have to rise if the desire to cheat was to be undermined.
Equally worrying for authorities is the murky nature of the people behind the corruption. The recent corruption in cricket was largely sparked by Asian-based betting syndicates. Officials in Europe are worried about eastern European gangs, citing the alleged involvement of Croatian betting rings in Berlin in the latest German scandal.
Another growing problem is that the result of matches no longer has to be fixed for a punter to clean up at bookmakers. It is now possible to bet on almost anything in sporting contests: who wins the toss in cricket, how quickly the first corner will come on football, even who will finish last in horse racing. This creates a whole series of other areas to be policed. When one English Premiership football team a few years ago booted the ball out of play almost straight from the kick-off, many asked whether some players had had a small flutter.
The DFB and German football are hoping that Hoyzer is just an isolated case so they can put this scandal behind them as cricket, baseball and all the other sports affected have done. But Hoyzer himself sounded less certain things were over. Ominously, he told German television that there were "a lot of other people" involved.