Police have questioned a passenger on a small commercial plane to a Michigan resort town after the crew reported he was acting suspiciously.

Police say crew members aboard the United Airlines flight from Chicago reported that the 28-year-old man had taken something into the bathroom, then left without it. Police say the crew also found a panel inside the bathroom had been tampered with.

They requested help from law enforcement on the approach to Traverse City airport.

There was also a report that the passenger had made a bomb threat, but a police official denied that. He also said a bomb-sniffing dog checked the plane and found nothing.

The passenger has been questioned by police and the FBI, but had not been arrested or charged Friday.

Another passenger aboard the jet calls the incident a complete misunderstanding.