Some 42 girls from Kent could be among the victims of a man facing child pornography charges in Canada, police in Ontario have said.
Ontario police outlined the allegations to reporters
Mark Gary Bedford, 21, of Kingston, Ontario, was arrested after three West Kent officers and local police executed a search warrant at his home.
He has been charged with 12 child porn and extortion offences.
It is claimed girls were contacted over the internet and persuaded to perform sex acts in front of their web-cameras.
Mr Bedford is in custody and due to appear in court in Ontario on Monday.
A computer system, floppy discs, CDs and other items were seized following the search of the property in Glengarry Road, Kingston.
Mr Bedford has been charged with two counts of luring a child using a computer, two counts of possessing child porn, three of making child porn, two of distributing it and three counts of extortion.
Canadian police told a media conference in Toronto that Mr Bedford allegedly hacked into the e-mail accounts of his young female victims to obtain address books listing potential victims.
If the girls, aged between nine and 15, refused his requests he would threaten to post their images on websites or show them to family members, officers alleged.
Police claimed his victims were threatened with bodily harm or death. They also said Bedford was unemployed, living at home with his parents, and spent a lot of time on the internet.
Inspector Steven Evans, from Kent Police, said the force became aware of the potential UK connection in April after a concerned parent contacted it.
Ontario Police Detective Sergeant Frank Goldschmidt said: "I have never seen this many victims involved, and I'm safe to say that at this point and time in this early stage of this investigation we're looking at well in excess of 100.
"It just seems that some of the kids that are involved in this type of activity these days really don't feel like they're doing anything wrong, because they're in the comfort of their own home.
"It amazes me to this day that parents allow their children to be locked up in their bedrooms with state-of-the-art computer equipment and then they get involved in this type of activity."
Officers have warned parents not to leave their children alone with computers equipped with webcams.
Chris Cloke, NSPCC head of child protection awareness at the National Society for the Prevention of Cruelty to Children (NSPCC), said: "The internet has opened doors for billions of people across the world.
"Unfortunately this means there will be many paedophiles prowling the net.
"It is vital that children and their parents understand and are alert to this risk. Stranger danger rules apply to the net too."