A pilot on the Condor Airlines Boeing 767 reported an in-flight emergency, and the fighter jets were sent as a precaution, said Air Force Capt. Ashleigh A. Peck, a spokeswoman for North American Aerospace Defense.
The plane landed safely, and one person was taken off the plane.
"All passengers are fine," airport spokesman Heath Montgomery said.
The FBI told ABC News that the incident was a "misunderstanding," and nobody was arrested or taken into custody, but no other details were available.
Carsten Stepanowicz (ste-PAN'-o-wits), a spokesman for the airline in Germany, said the pilot requested help because of an unruly passenger on board.
"It was not possible to go on with the flight, so the pilot decided to land in Denver," he said. He said he could not release details on the number of passengers.
The FBI did not return a phone from The Associated Press seeking comment.
The incident occurred shortly after 6 p.m., Montgomery said. The Transportation Security Administration and Denver police met the plane at the gate, and the FBI was notified.
The plane resumed the flight to Germany after refueling.