(CNN) John Geddert, a US Olympic coach in 2012 and onetime owner of an elite Michigan gymnastics club, is the subject of a police investigation, Eaton County Undersheriff Jeffrey Cook said this week.

Cook wouldn't comment on the nature of the ongoing investigation.

Eaton County Sheriff spokeswoman Jerri Nesbitt said people have come to them with complaints about Geddert. Nesbitt wouldn't comment on the type of complaints, type of investigation or how many people have come forward.

Geddert's attorney, Chris Bergstrom, did not return calls for comment Wednesday. According to media reports, Geddert released a statement last year saying he had "zero knowledge" of the sexual abuse committed by Larry Nassar, who volunteered at his gym.

Eaton County Prosecuting Attorney Doug Lloyd told CNN he is aware of the investigation but has not been briefed on details.