The passenger, reported by The Denver Post and CBS News to be Czech model Zaneta Hucikova, is now sitting in an immigration detention centre on suspicion of a visa violation.

Reports said the woman had the cat in her purse when she boarded the Condor Airlines Boeing 767 flight from Las Vegas to Frankfurt.

Cabin crew decided to put the cat in a toilet, at which point the woman became enraged and punched a female flight attendant in the face.

Passenger Dashenka Giraldo told ABC News in the US: "She said that she was part of the Mafia and that the mafia follows her around the world and that she was able to bring the plane down if that needed to be the case if she couldn't see her cat."

Following the threat, the pilot alerted authorities and two F-16 fighter jets were scrambled from Buckley Air Force Base in Colorado.

The incident happened over Wyoming about 6pm on Friday (local time).

Passenger Fritz Peterson told CBS: "That lady wasn't happy with the crew putting their cat in the lavatory and then everything went wrong. She started screaming and shouting in the back."

A Condor spokesman said it had not been possible to continue with the flight, so the plane was diverted to Denver International Airport, where it landed safely, escorted by the F-16s.

Passengers were put in hotels in Denver for the night, with the flight resuming the next day.

The FBI said it decided the disturbance was a customer service issue, and was not life-threatening.

"The airline handled the matter according to their policy for customer service related matters. No arrest was made."

However, CBS and Denver Post reported that Hucikova was in immigration detention for overstaying a visitor's visa.

CBS said that one online posting said she called Las Vegas her home.

Apparently the cat is in federal custody.

Stuff.co.nz