About 25 separate investigations of suspected corruption linked to FIFA and World Cup bidding are being led by federal prosecutors in Switzerland, the country's office for the attorney general said Friday.
The office of Michael Lauber confirmed the scale of "football-related cases" after securing a first conviction since its FIFA probes began in 2014.
Cases were not specified, but criminal proceedings are open against former FIFA officials Sepp Blatter and Jerome Valcke, and some 2006 World Cup organizers, including Franz Beckenbauer.
Swiss and American prosecutors worked together on a guilty plea made in a Brooklyn federal courthouse on Thursday by Jorge Arzuaga, a former employee of Swiss private banks from Argentina.
Arzuaga admitted to working with former FIFA finance chairman Julio Grondona and others in a money-laundering conspiracy linked to bribes. Grondona was senior vice president at FIFA when he died in 2014.
Arzuaga forfeited $650,000 in "unlawfully obtained" bonuses to the Swiss treasury, the federal prosecution office said.
The banker, who worked in Zurich for Credit Suisse and Julius Baer, is due to be sentenced on Jan. 4.
Lauber was invited by FIFA in November 2014 to begin investigating suspected wrongdoing in the 2018 and 2022 World Cup bidding contests which were won by Russia and Qatar, respectively.
"To date, 178 reports of suspected money-laundering transactions have been received in connection with the football investigations," Lauber's office said.
In May 2015, the scope of Swiss and American cooperation to prosecute corruption linked to FIFA was revealed when seven officials, including two FIFA vice presidents, were arrested in early morning hotel raids in Zurich. FIFA was also raided for evidence that day.
A further round of arrests, indictments and guilty pleas to U.S. courts were revealed in December 2015. More than 40 soccer and marketing officials have been indicted or made guilty pleas in the American case.
In Switzerland, authorities are now analyzing "seized documents containing some 19 terabytes of data," Lauber's office said Friday.