U.S. authorities say their online portrayal of Ontario as a haven for child-sex tourism helped them catch four predators.

The controversial website set up by the Department of Homeland Security was for the bogus firm Precious Treasure Holiday Co., which promised to arrange illegal encounters in Ontario for pedophiles.

The 19-month-long undercover operation yielded more than 140,000 hits and led to four arrests and convictions, but it has come under criticism on this side of the border because of how Ontario was depicted.

A screen grab from a bogus sex-tourism website built by U.S. agents claimed that Canada was safe for pedophiles in a sting operation to nab prospective child sex criminals. (TheSmokingGun.com)

Brian Moskowitz, the U.S. special agent in charge of Homeland Security Investigations for Michigan and Ohio, defends the portrayal, saying it was created to strengthen the sting scenario.

Canada used for 'mystique'

"Canada wasn't picked because it's perceived to be less risky, or this would be permitted in Canada," he said. "It was just to add to the mystique of the scenario."

Moskowitz noted that the Precious Treasure website used symbols and coded language known in child-sex circles to draw in predators. The aim was to nab pedophiles seeking arranged trips to Canada from Cleveland, Ohio, for the purpose of molesting children.

To avoid the possibility of entrapment and to prevent visitors from stumbling on explicit photos or offers to provide children, a user could only access such content after repeated emails to the undercover agents, Moskowitz explained.

"No one could stumble into this and accidentally get ensnared," Moskowitz said. "You had to proactively ask, in accordance with our laws."

Windsor removed from website

Windsor police were among those in Canada who were alerted to the ruse so they wouldn't waste resources chasing a phantom website.

Even so, Jerome Brannagan, deputy chief of operations with the Windsor police, said he was uncomfortable enough with the website to request that U.S. agents remove references to Windsor. Other Canadian references remained.

"We understand the basis for why they chose to do it that way," Brannagan said. "However, that was some concern of ours because we're certainly not trying to attempt to suggest Canada is the place to come to for that type of criminal behaviour."

The fake website was outed by The Smoking Gun as a government sting, but investigators had already gathered enough evidence to convict four men.

One has already been sentenced to 20 years in federal prison for attempting to travel to engage in illicit sexual conduct with an eight-year-old girl and for the attempted receipt and distribution of child pornography.

Three other men will be sentenced later this month.