MUNICH, GERMANY – Tourists at Munich’s Oktoberfest got more than the price of admission when a fairground Ferris wheel was used as the impromptu location for a pornographic film, police said Thursday.

Three Italian tourists were enjoying the view across the rooftops of Munich from the vantage point in a Ferris wheel gondola when a female passenger disrobed and engaged in sexual activities while a cameraman and a production assistant looked on.

The tourists alerted authorities, who detained the trio. They were identified as a 21-year-old registered nurse, a 25-year-old university student and a 30-year-old political sciences teacher.

They were later released after explaining that they had been engaged in a sociological experiment to measure public responses to unexpected behaviour.

Oktoberfest, billed as the world’s biggest beer party, opened last weekend. Some six million visitors are expected to have attended the fest by the time it closes on October 3.