A 17-year-old foreign exchange student reported missing last week was found safe on Sunday after “cyber kidnappers” extorted $80,000 from his family in China.

Riverdale police said Kai Zhuang was “manipulated and controlled” by “cyber kidnappers” who led him to believe that his family was threatened, KSL reported. The family paid the money after the “kidnappers” sent “continuous threats,” including a photograph that made it appear the boy “was being held captive and in danger.”

A detective found him on Sunday in the mountains near Brigham City, where he was  “alive but very cole and scared.” Riverdale police said they believe he had been “self-isolating” in a canyon near Brigham City.

Police launched a search for the boy after his family reported receiving a ransom note and the photo. Initially reports said only that he was possibly being held against his will, as CrimeOnline reported.

But the FBI told police they had worked several recent cases in which “cyber kidnappers” target Chinese foreign exchange students by telling the students to isolate themselves and take photos that make it look like they’re being held captive, which they’re told to send to their families, KSL said.

Riverdale police tracked Kai’s bank records and purchases over the last month as well as tracking his phone records and discovered a recent encounter with police in Provo when he was discovered trying to set up a campsite.

On Sunday, detectives tracked him to his remote campsite outside Brigham City.

“The victim was relieved to see police” Riverdale Police Chief Casey Warren said. “The victim had no heat source inside the tent, only a heat blanket, a sleeping bag, limited food and water and several phones that were presumed to be used to carry out the cyber kidnapping.”

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[Featured image: Riverdale detectives speak with Kai Zhuang after finding him/Riverdale Police Department]