Testimony from a former ESPN executive is underscoring the high stakes and corruption that has enveloped the world of soccer.

The U.S. government’s star witness in a big-money bribery case engulfing the world of soccer has begun testifying at the trial of two former Fox executives accused of paying bribes to rig the bidding process for broadcasting rights to two of the sport’s biggest competitions.

Two former Fox executives are on trial, accused of bribing South American soccer officials for TV rights to one of the continent’s biggest annual tournaments and using information gathered in the process to help the network’s winning World Cup broadcast bid.