LAUSANNE, Switzerland - Child pornography was downloaded from a Swiss hip-hop music website to around 2,300 computers in 78 countries, Swiss police said on Monday.

Jean-Christophe Sauterel, a police spokesman in the Vaud canton of Switzerland, said videos of minors engaged in sexual acts were hidden in a Swiss site where the principal content was "perfectly legal."

Those accessing the illegal material through a portal on the hip-hop page site paid US$10 ($14.50) to download one video and US$500 for the full collection of 101, with proceeds going to operators in Russia, Sauterel told Reuters Television.

"It's through that site, without the owner of the site knowing, that the files were implanted," he said in an interview in his office in Lausanne. "It is the first time in Switzerland that we are confronted with this kind of case."

The investigation, triggered by a tip-off from Interpol, took place between May and July 2008, Sauterel said.

He said there had been arrests in the United States and in Poland. The address of the website involved was not made public.