A Canadian accused of running a sex tourism business in Thailand involving young boys has been arrested in London, and now faces charges of child pornography.

John Wrenshall, 62, was arrested at Heathrow Airport early Monday, according to a report in The Globe and Mail.

U.S. authorities allege Wrenshall operated a brothel at his home near Bangkok, and catered his business to international clients.

The investigation apparently dates back to 2005, when Canadian investigators found explicit images of child abuse on the Internet. They traced the images to a U.S. citizen named Wayne Nelson Corliss, who eventually pled guilty to several sex charges.

Corliss said he had participated in a sex tourism scheme, according to the Globe report. He claimed he had abused children at the home of Wrenshall, along with two others.

None of the allegations against Wrenshall have been proven in court.

The U.S. Department of Justice claims that Wrenshall has run a brothel since about 2000, inviting clients to stay at his home and telling them he would use the money "to support the boys."

He is now being held in custody in Britain and faces extradition to the U.S., where he faces 18 charges relating to child pornography and sex tourism.