"This is typical organized crime behavior: attract people, corrupt people and finally intimidate them.

"I think police have finally realized that this is organized crime and therefore they have an interest. Most of these investigations in Europe happened accidentally. They were investigating crime in other areas and came across this issue of match-fixing.

"There's been no determined effort to have preventative investigation, it's been retrospective. We need to find out who's involved and stop them -- in fact, to prevent them."

A former player who helped expose match-fixing in Italy in 2011 says clubs also need to take more responsibility.

"The management of the clubs have to act and support the players and support the authorities in their investigations," said Simon Farina, who now works as a community coach for English club Aston Villa.

"They cannot leave the players isolated and afraid to speak out when they are confronted by the wrong individuals," he told the Premier League team's website.

Farina was recognized by Interpol after telling the authorities he had been offered a bribe to fix the outcome of an Italian Cup game in November 2011, and was later called up to Italy's national team as a reward.

"Working now with children, I understand completely how important it is to pass on the right values," he said.