More than 150 police swept into 32 premises throughout Germany in early morning raids and seized evidence although no arrests were made, the Berlin prosecutor's office said in a statement.
"The suspects are under investigation for manipulating the results of at least 10 matches in the first, second and third division as well as the [2004] German Cup," the prosecutors office said in a statement. "Evidence was successfully secured today."
A total of 25 people are suspected of manipulating those matches to favor betting on the games, it said.
As well as disgraced referee Robert Hoyzer, prosecutors are investigating Juergen Jansen, who normally referees matches in the Bundesliga's top division, as well as match officials DavidM, Felix Zwayer and Dominik Marks, the office said.
Hoyzer's admission last month that he had rigged matches set off Germany's biggest sporting scandal in more than 30 years.
