A fake ritual killing filmed in a courtyard at Cern, the Geneva particle physics research complex where the Large Hadron Collider is situated, has prompted an investigation by the European Organisation for Nuclear Research (Cern). A spokeswoman suggested users of the facility had “let their humour go too far” and warned of the potential for “misunderstandings about the scientific nature of our research”.

The video, leaked online, shows several individuals in black cloaks gathering in Cern lab’s main square, in front of a statue of the Hindu deity Shiva that is on permanent display at the complex, home of the Large Hadron Collider. The individuals participate in what appears to be a re-enactment of an occult ceremony. It includes the staged “stabbing” of a woman. The video is filmed from the perspective of a “hiding” viewer watching from a window above who, as the ceremony reaches its climax, lets out a string of expletives and flees with the camera still running.

“These scenes were filmed on our premises but without official permission or knowledge,” says a Cern spokeswoman told Agence France-Presse.

“Cern does not condone this type of spoof, which can give rise to misunderstandings about the scientific nature of our work.”

According to her, the investigation under way was an “internal matter”.

“Cern IDs are checked systematically at each entry to the Cern site whether it is night or day,”says France-Presse, responding to concerns about Cern’s security raised by the video.

“Cern welcomes every year thousands of scientific users from all over the world and sometimes some of them let their humour go too far. This is what happened on this occasion.”