Inside a massive, international betting scheme

Investigators say Joseph Vito Mastronardo Jr. was behind a major sports bookmaking empire with money flowing to Sweden, Malta and Costa Rica, and among other locations.

IRS Special Agent Paul Schnaufer told CNBC, "there were dozens of bank accounts, hundreds of check transactions and dozens of wires that went overseas."

Mastronardo accumulated so much cash that some of it was buried in his backyard, investigators said.