Spanish police arrested 121 people in the country's biggest-ever crackdown on child pornography, seizing discs containing millions of video and photo files shared by a network that distributed them in 75 countries, authorities said Wednesday.

Two of the suspects produced pornographic material themselves using members of their own families, police said in a statement. Those arrested came from all kinds of backgrounds, including pilots, salespeople, porters, taxi drivers and bank employees, it said.

The arrests were made last week and four of those in custody are minors, police said.

Brazilian police helped with the operation, which began in July 2007. A further 96 people have been named as suspects in the case, which involved raids on more than 250 homes across Spain.

Some of the videos and photographs that were seized featured extremely disturbing material, police said.

Most of the suspects are Spaniards, police said without naming the other nationalities. Police said the detainees used peer-to-peer, or P2P, servers to share at least three download sites.

Spanish authorities said they have arrested more than 1,200 people in connection with child pornography on the Internet in the last five years.