Two German men were jailed for life in April, 1999 for murdering a prostitute to make a "snuff" movie. The woman was tied up, raped and tortured before being strangled and her ordeal captured on video. It was cheaper than employing actors and special effects, a court in Hagen, Germany, was told. Ernst Dieter Korzen, 37, and Stefan Michael Mahn, 30, picked up the 21-year-old Turkish prostitute in Cologne and took her to their isolated farm. Her body was later found on a rubbish tip, her hands and feet bound with metal and a rope round her neck.

The court heard the crime was uncovered because the woman died too quickly and a second woman was abducted to complete the video, but managed to escape and alert police. It is the first time anyone has been convicted of a murder captured on film. Prosecutor Wolfgang Rahmer said: "From my experience, this represents a new depth in perversion. You see the victim begging for her life, pain being inflicted and massive sexual torture." Before this case, lack of evidence had led to scepticism over the existence of snuff movies.

But Mr Rahmer said he had no doubt that an industry existed. "We know that there is no sexual perversion that cannot be marketed, and you would be amazed at the sums offered for such perverse videos." Frankfurt prosecutor Job Tilmann said the film would have fetched up to £10,000 in America. "People soon get bored and then the perversion escalates. There is no limit to the cruel fantasies that can be shown." Belgian private eye Andre Rogge, who specialises in missing children, said the German case was not an isolated one."I know from my experience that this is a thriving market. On some videos you can see children under four being tortured. But police have been unable to identify any of the victims."