Federal agents executed search warrants at several Detroit area locations on Tuesday including a medical marijuana facility owned by a businessman who owns a long-closed auto plant that has become a symbol of Detroit's decline.

The Drug Enforcement Administration, state and local law enforcement agencies conducted the searches at offices in northwest suburban Detroit, Andrew Eiseman, group supervisor for the DEA in Detroit, said.

Eiseman confirmed searches were conducted at two Caregivers of America LLC medical marijuana offices, but would not confirm other locations searched on Tuesday under sealed warrants.

"It's a brand new investigation," Eiseman said. "It's ongoing at this point so we really can't confirm anything."

Eiseman declined to say whether the searches were being conducted as part of a state or multistate investigation.

Detroit-area businessman Romel Casab is listed as registered agent for the medical marijuana office in Novi that was raided on Tuesday, according to state business records.

Casab could not be reached for comment.

Bioresource Inc., which listed Casab as president, claimed ownership of the long-shuttered Packard auto plant that has figured prominently as a backdrop in television shows and recent movies in a lawsuit last year.

The company sued a local nonprofit studio in Wayne County Circuit Court for allegedly removing a mural painted on the plant property by the artist Banksy.