Nunez's signed statement was delivered to the Central Electoral Board, whose president made the announcement Friday, according to an account from Dominican Today, an English-language online newspaper.
In his announcement, Robert Rosario said several people have been detained and several more are wanted for questioning in the matter.
Emails to spokesmen for the Marlins and Major League Baseball were not immediately returned Friday afternoon.
Nunez was placed on Major League Baseball's restricted list Thursday and will not pitch the remainder of the season.
The right-hander, who has pitched in the majors since 2005, was 1-4 with a 4.06 earned run average and a career-high 36 saves in 68 appearances out of the bullpen for the Marlins this season.