Britain's leading cybercop has slammed European Union data processing legislation which he says makes it impossible for police to smash online crime rings.

Speaking at a European Commission forum on cybercrime, Detective Chief Superintendent Keith Ackerman, chairman of the UK Internet Crime Forum, said that police were unable to track down 500 members of a child porn ring because of the law requiring Internet Service Providers (ISPs) to erase traffic data.

Ackerman also said that the law hinders police as they try to track down the sending of racist emails.

"This is a data retention issue not a data protection one" Ackerman told vnunet.com. He said that he was concerned that the existing 1995 EU directive on the processing of personal data, which came into force in 1998, made it harder for the police to track criminals.

The EU is considering amendments to the existing directive, and Ackerman is concerned that changes could make it even harder for the police. The directive requires ISPs to delete all traffic data after a call, unless that data is needed for billing purposes. Ackerman said that this meant that pay-as-you-go ISPs did not need to keep records.

Speaking at the EU forum, Ackerman said that as a result of information from another country the police had been able to ascertain that about 500 people are involved in the exchange of "vile pictures." But he said that when police tried to track these users, many of whom are outside the UK, they drew a blank.

"The information that would be vital to detect these offenders has been lost forever" he said.

Despite the directive, EU member states can order ISPs to store data traffic when they considered it necessary to fight crime.