At least 22 people were put under arrest on Tuesday by the Ontario Provincial Police in what seems to be the biggest child pornography investigation ever conducted in Canada.

The investigation started in January. Twenty five were executed in 16 communities in the region. The Ontario police issued 73 criminal charges. The investigation is under way and four other suspects may be arrested, police officials said in a statement.

"Fair warning to pedophiles: you can run, but you can't hide. Sooner or later, we will identify you, we will arrest you and we will bring you to justice." This is what the warning Ontario Provincial Police Commissioner Julian Fantino gave during the news conference sounded like.

The Ontario Provincial Police (OPP) collaborated with 18 municipal police forces from across Ontario and with the Ministry of Community Safety and Correctional Services and the Ministry of the Attorney General in the investigation.

Among the charges brought against the detainees were: possession of child pornography and distributing child pornography, child luring charges, drug and weapons offenses. Twenty men, one woman, and one teen face the above-mentioned charges in the case, officials said. The men involved in the case range in age from 20 to 64.

During the period stretching from April 1 to December 31, 2007, OPP child pornography task force looked into 1515 cases and laid 539 related charges, authorities said.

Canadian and US police forces collaborated and said they managed to trace pornographic images involving children to more than 205,000 unique computer addresses in Canada.

Detective Staff Sergeant Frank Goldschmidt, coordinator of the Ontario police child pornography task force, labeled the case as and the massive arrests made as  "the largest coordinated child pornography sweep in the history of Ontario," and of Canada.

Using software developed by Flint Waters, a special agent with the Wyoming attorney general, to uncover IP addresses of suspicious sites, a survey as carried out in Canada’s largest province. The technique helped police find out that at least 4,000 computers in Toronto are involved in trading images of child sexual abuse. About 15,000 computers are taking part in such activities in Ontario, and about 45,000 nationwide.