The grandfather of a 6-year-old boy who was abducted last month was accused of squirreling away millions of dollars skimmed from a U.S.-Mexico drug smuggling operation using a hidden compartment in a camper.

Clemens Fred Tinnemeyer, 51, and his girlfriend, Terri Lynn Leavy, 42, were charged with interstate and foreign travel or transportation in aid of racketeering enterprises — a felony that prosecutors said is punishable by up to five years in prison and a $250,000 fine.

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The two were being investigated by federal drug enforcement agents when the boy, Cole Puffinburger, was abducted Oct. 15, according to a criminal complaint unsealed during their appearance Monday in federal court.

Police had said two gunmen who posed as police officers tied up the boy's mother and her boyfriend, ransacked their Las Vegas home and took the boy when they couldn't find money Tinnemeyer allegedly stole from Mexican drug traffickers.

The boy became the focus of an intense search in neighboring states before he was found unharmed late Oct. 18 on a Las Vegas street.

Tinnemeyer was arrested Oct. 17 as a material witness in the kidnapping by federal agents in Riverside, California, who found some $3.5 million in cash bundled in suitcases, footlockers and a handbag in a storage locker in nearby Menifee, according to the criminal complaint.

Leavy was arrested as a material witness two days later.

Neither was asked to enter a plea Monday, although their court-appointed lawyers said after the hearing they intend to fight the federal racketeering charges.

Federal Magistrate Judge Robert Johnston deemed Tinnemeyer and Leavy flight risks and a danger to the community and ordered them held in federal custody without bond pending a preliminary hearing Nov. 17.