The growing importance of betting means that sport is more exposed than ever to the risk of manipulation, the United Nations said on Thursday.
National and international networks exist "to manipulate competitions through bribery, coercion and threats to referees, players and club officials," according to a study by the UN Office on Drugs and Crime in Vienna.
The number of suspected cases has increased significantly over the past 20 years and no country, sport or level of play is spared, the report added.
The development is exacerbated by the fact that criminal organizations use the betting business to launder money.
According to estimates, up to 140 billion dollars is reintroduced into the legal money cycle each year through sports betting.
Money laundering
"Given the scale of illegal betting operations, the industry is highly attractive for transnational criminal groups to launder money," the agency said.
Popular targets for betting manipulation include football matches, especially in lower-tier leagues.
