European police say they've identified some 680 suspicious football matches including World and European Cup qualifiers and Champions League games in a global match fixing scandal spanning 2008-2011.
Europol's chief Rob Wainwright says the biggest investigation ever into suspected match-fixing involved at least 425 referees, players and other officials.
Most of the allegedly fixed matches in Europe were played in the Turkish, German and Swiss championships.
Criminal gangs are believed to be involved in match-fixing networks, using them as a way to launder cash.
Last year the head of an anti-corruption watchdog estimated that $US1 trillion was gambled on sport each year - or $3 billion a day - with most coming from Asia and put on football matches.