Hidu, the electronic-sniffing dog, helps fight kiddie porn in pedophilia case in Mexico City

Hidu, an electronics detection dog, was lent by the U.-S.-based anti-sex-trafficking group Operation Underground Railroad to help Mexico City prosecutors in an investigation of a suspected Dutch child pornography promoter. (Operation Underground Railroad via AP)

MEXICO CITY — An unusual alliance of international activist groups, Mexican prosecutors and a dog that was trained in Indiana to sniff out memory devices joined forces to catch a high-profile suspected pedophile in Mexico City.

It started when Free a Girl — a Netherlands group that fights human trafficking — tipped off activists with the U.S.-based Operation Underground Railroad that Jason Maatman, a Dutch man who openly advocated sex with children, had gone to Mexico after fleeing authorities in the Netherlands.