A nurse and two cameramen were arrested at the Munich beer festival for filming a porn movie on the city's famous big wheel.

The 21-year-old registered nurse, unnamed due to German privacy laws, and her two acquaintances were spotted 'filming sexual acts' by three Italian tourists in another carriage of the ride.

The Oktoberfest tourists alerted authorities, who detained the nurse and the filmmakers - a 25-year-old student and a 30-year-old teacher.

Munich police released a statement saying: The trio were spotted in the carriage with filming equipment.

The 21-year-old suddenly disrobed and produced a sex toy that she began to use while the other two filmed her.

The three have been charged with public indecency.