A sweeping global child exploitation investigation has led to more than 150 arrests around the world and either charges or convictions against 16 Canadians, Toronto police said Thursday.

The probe, dubbed Project Mercury, took place over more than three years. It was aimed at stopping the alleged sexual abuse of children that was being shared online via livestream and involved victims as young as 10 months old, police said.

Toronto Police Staff Supt. Myron Demkiw said the project took a significant toll on investigators, but was essential both for the safety of the affected children and the knowledge of the public at large.

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“It’s important to understand that this is happening to children all over the world,” Demkiw said at a news conference. “That they are not only being sexually abused, there are also permanent recordings of this abuse being distributed by people around the globe for their sick perversion.”

Project Mercury’s roots go back to 2014, when investigators in the U.K. uncovered a network of people allegedly livestreaming, recording and distributing instances of child sexual abuse.

Toronto Police Det. Const. Janelle Blackadar said at least one of the alleged victims in that case was a mere infant at the time.

The U.K.’s National Crime Agency identified one of the alleged participants as a Toronto man, leading to the involvement of local police.

City investigators ultimately arrested him and laid a total of 10 charges, at least some of which he was ultimately convicted of, police said.

After recovering evidence from the man’s computer, Blackadar said numerous forces across Canada collaborated with the National Crime Agency and Homeland Security Investigations in the U.S. to get Project Mercury off the ground.

During that time, Blackadar said investigators documented at least two other instances of child abuse being broadcast live to participants who took part in the abuse. In at least one case, she said an eight-year-old child had been drugged.

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“The sexual abuse ... occurred not only for the sexual gratification of the abuser himself, but also to satisfy requests from those online who then actively encouraged the abuse while it was happening live,” she said.

One of the alleged perpetrators in that case was arrested in Pennsylvania, the other in Saskatoon, Blackadar said, adding Canadian authorities are currently working to have the Saskatchewan man branded a dangerous offender.

Overall, participants in Project Mercury said the investigation netted 153 arrests and led to the rescue of dozens of children.

The tally of arrests includes 16 Canadians, most of whom live in Ontario. Besides suspects from the Ontario communities of Toronto, Belleville, Ottawa and Thunder Bay, however, police said Canadians were arrested in Newfoundland and Labrador, New Brunswick, Quebec, Saskatchewan and Alberta.

None of the Canadians arrested held positions of public trust, police said, but that did not hold true in other jurisdictions.

Graham Ellis of the National Crime Agency said the 79 British suspects arrested in the probe included four teachers, a doctor, a member of a police force, a nurse, a priest and a private music tutor.

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Ellis said British police also prevented a child from being adopted by an offender and removed another from foster care.

U.S. authorities arrested 58 suspects, according to Homeland Security Investigations Attache Melissa Ruiz.

She said would-be abusers should heed the results of the large-scale investigation as a warning, stressing that international borders do not present a major barrier to officials working on exploitation cases.

“If you’re a predator, know that we will find you, arrest you, and ensure that you face the full weight of the law,” Ruiz said. “Today’s united front between Canada, the United Kingdom and the United States is a message to the world that we will not relent when it comes to protecting our children.”