A German court opened proceedings on Tuesday in a case that could define local responsibility for pornography available through the Internet.

After nearly three years of investigations and pre-trial hearings, the former head of the German division of CompuServe on-line service, spent his first day in court to defend himself against charges of distributing child pornography and other illegal materials.

Prosecutors alleged that Mr Felix Somm (34), should be held responsible because CompuServe provided access in Germany to illegal pornographic pictures and Nazi texts that were available via the Internet from computers in other countries.

Mr Somm, who left CompuServe last year and started his own electronic commerce consulting firm, said he expected to be cleared of the charges.

"I am convinced that this court process will prove my innocence," he said in a statement. "The charges are based on a misunderstanding of the structure of the Internet and the roll of service providers."

Mr Somm, who left CompuServe last July, also said he notified German authorities about the illegal material and helped them in their investigation.

He was supported by a university professor who said that the multimedia law that came into force in August last year made clear that on-line service providers are not responsible for the content of the Internet.

"The accused is not the originator of the illegal data, and intensively supported the Bavarian police in tracking down the originators," said Mr Ulrich Sieber.

Under Germany's Information and Communications Law, Internet access providers generally are not held reliable for banned material on the Internet.

It requires companies that provide access and Internet content to take reasonable measures to block banned material, like Nazi literature.

According to Mr Somm's attorneys, CompuServe provided its subscribers with software that blocks access to offensive material.