Nine Canadian men have been arrested as part of a worldwide crackdown on people who shared child sex videos over the Internet, police said Tuesday.

Royal Canadian Mounted Police Supt. Earla-Kim McColl said the arrests were part of an ongoing investigation code-named Project Koala, which has implicated about 2,500 people worldwide.

The videos, ranging from girls in provocative poses to a father raping his young daughters, were sold to clients in 19 countries including teachers, doctors, lawyers and computer experts, said Menno Hagemeijer of the pan-European police organization Europol.

The operation included Germany, Italy, Belgium and Britain. European authorities revealed in November they arrested more than 92 men. France announced 20 arrests last year.

The ages of those used in the videos ranged from 9 to 16, and most were Ukrainian girls duped into performing sex acts with promises of lucrative modeling careers.

Among the Canadians arrested are a former Scout leader from the Toronto area, a man from Edmonton who had movies in his possession, and a Victoria resident whose home had a telescope overlooking a school yard.

McColl said they are about 50 more ongoing investigations in Canada related to Project Koala.

"Historically, people with sexual interest in children would be somewhat isolated in their community. Finding materials would mean risking exposing themselves potentially if they go into a book store or are making a mail order," McColl said. "The internet provides them anonymity and it also provides them an opportunity to network with other offenders who validate their feelings and tell them what they are doing is OK."

The investigation was triggered by the Australian police discovery in July 2006 of a video depicting a Belgian father raping his daughters, aged 9 and 11.

The alleged mastermind, Italian Sergio Marzola, and the Belgian suspected of abusing his children, were arrested in 2006.

Marzola, 42, allegedly made some 150 videos in Ukraine, the Netherlands and Belgium. He was arrested in 2006 in Bologna a day before he was due to move permanently to Ukraine, where prosecutors say he ran a studio for producing the abuse films.

Police say he sold the videos online. Customers mainly paid using the Internet and were sent links and passwords allowing them to download the films, police said. Those from countries with slow Internet connections sent cash and were mailed DVDs. When police raided his home, they $100,000 in cash.

Some of Marzola's customers also sent requests for particular poses and even slips of paper bearing their names for "models" in the videos to hold, police said. Others sent underwear for them to wear and Marzola allegedly auctioned off the lingerie used in some of his shoots.

Customers paid extra to be present while films were shot, while others sent gifts of poetry and jewelry to their favorite girls, he added.