The man removed from a flight to Detroit posed no security risk to the plane, a law enforcement official said Sunday night.
The official said the passenger was taken into custody after becoming verbally disruptive on landing. Subsequent interviews by investigators determined he was a businessman who became ill during the flight.
The official was not authorized to discuss the investigation and therefore spoke on condition of anonymity.
The incident occurred on board the same Northwest Airlines flight from Amsterdam that was attacked on Christmas Day. The pilot of the Sunday flight requested emergency assistance upon arrival.