MEXICO CITY—The World Boxing Council says former flyweight boxing champion Isidro "Sid" Perez has been missing for months and his whereabouts are unknown.

The Mexican citizen held the flyweight crown between 1990 and 1992. His record at retirement was 57-9-3.

A statement Wednesday from the Mexico City-based boxing group says that neither Perez's friends nor his family have heard from him in months. It says Perez has not cashed a pension check since September.

The council calls the situation "very worrisome," but does not say whether a missing person report or criminal complaint has been filed in the case.