The head of the Federal Crime Office, Joerg Ziercke, said the distribution of videos and photographs featuring juveniles in sexual situations rose 55 percent in Germany between 2006 and 2007, most of them on commercial websites.

He said other European countries had managed to stem the flow of such images by blocking access to offending sites, adding that voluntary schemes with the Internet sector had been ineffective in Germany. “I think we are only going to make headway with a legal requirement,” he told reporters at the presentation of an annual report on organixed crime. “Experts say it is technically possible to block access and there is no opposition from the European Union. So why do we have nothing in Germany?”

Currently authorities have to work with Internet providers when illegal content is discovered on a website. Ziercke said access blocking would allow police to take direct action. Last year German authorities reported 11,357 child pornography offences, up from 7,318 the previous year. The number of cases on the Internet more than doubled in the same period, to 6,206 cases.

Ziercke said the trade produced millions of euros in revenue every month with “younger and younger” victims. He said Norway, for instance, had had enormous success with access blocking, netting some 15,000 attempts to find child pornography online each day. Other countries with access blocking laws on the books include Denmark, Sweden, Finland, Italy, Switzerland, Britain, Canada, New Zealand, South Korea and Taiwan, according to Ziercke.

In the United States, access providers participate on a voluntary basis, while the Netherlands, Belgium, Ireland, Iceland, Poland, Australia and Japan are considering legal crackdowns, he said. “I have the impression that we will soon have to justify why we are not taking the lead,” Ziercke said.

A government spokesman said there were already legal mechanisms to take action against websites “on a case by case basis,” adding that any question of new legislation would be better taken up by the EU rather than Germany alone.

The German Internet Industry Association (eco) insisted the sector took the problem seriously and had been working for years with authorities to stamp out illicit images of minors and other banned content. Eco president Harald Summa said it was more effective to continue the current practice, with an online complaint centre collecting reports of offensive contact by Internet users and handing them over to authorities. “We want to continue this effective cooperation,” he said in a statement. Internet users who wanted to find child pornography would be able to get around “access blocking,” Summa added.