Police in the UK are claiming a major victory in their fight against Internet pornography after a judge ruled that the content of American Websites can come under British jurisdiction.

Chief Supt Martin Gauch explains the ruling

A 28-year-old businessman, Graham Waddon, from Sutton, just south of London, pleaded guilty to running the UK's largest Internet porn operation after Judge Christopher Hardy made the landmark ruling at Southwark Crown Court.

Waddon had set up a series of Websites in the US portraying extreme pornography, with names such as Farmsex, Europerv and Schoolgirls-R'us.

He ran the operation from his terraced house in Sutton, charging customers £25 a month for access to the sites. One site alone made him more than £1.5m in a year.

Judge rules publication in UK

Peter Sommer, defence expert in the case: Wrote explanatory paper for the judge

His defence argued that publication of the material was outside British jurisdiction. But the judge said publication took place in the UK when Waddon transmitted the material to the Websites and when police downloaded it.

He also rejected defence claims that the pornography evidence was inadmissible. Under the Police and Criminal Evidence Act of 1984, every computer involved had to have a certificate stating it was working properly at the time.

But the judge ruled that this could involve hundreds of terminals in other countries and would present police with an "impossible task". He took the view that only the computer receiving the material - in this case, the own owned by the police - needed to have the certificate.

Waddon then admitted 11 sample counts of publishing obscene articles on the Net and one charge of possession of an obscene video featuring a dog. The case was adjourned until 30 July for pre-sentence and medical reports.

Massive implications, say police

PC Neal Ysart of the Obscene Publications and Internet Unit said afterwards: "This was the biggest Internet porn operation busted so far in the UK, and one of the largest in the world.

"Waddon deliberately set up his Website in America ... hoping that would shield him from prosecution in this country.

"But the judge's findings mean he and others like him who try to avoid prosecution by placing this material abroad are making a big mistake. They will be prosecuted.

"As far as we are concerned, this was a test case. This is a major victory. If we had failed to get the ruling that we got today it would have opened up the floodgates, not only for Internet pornography, but for anyone using the Internet for crime. It has massive implications for the fight against crime of all sorts."

Precedent set - cyberlawyer

Alistair Kelman, a barrister specialising in Internet law, agreed that a precedent had been set.

"It is of great significance in relation to the prosecution of pornographic material on the Web and I've no doubt this case will be followed in similar circumstances," he told BBC News Online.

"I don't think it would be creating a precedent in terms of copyright infringement and also in cases where the chain of custody is essential for proof of dishonesty - that is, looking at date and time stamps to link things together."

On the ruling on computers needing certificates, Mr Kelman said he thought the point of law had been glossed over in this case.