Story highlights 30-40 graves found in region known for human trafficking

Lone male survivor is "very sick" and has been hospitalized

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Bangkok (CNN) At least 30 graves containing human remains have been found in a "detention camp" in southern Thailand, along with a lone male survivor, Thai authorities said.

The survivor is "very sick" and has been hospitalized, said Thai police spokesman Lt. General Prawut Thavornsiri. Police have not been able to interview the survivor yet and aren't sure of his nationality, but they believe he is Burmese.

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Thai authorities learned about the camp from a suspect who tipped them off, Thavornsiri said. He would not say whether that suspect was linked with human trafficking.

"It is still under investigation," Thavornsiri said. "I can't reveal much information yet."

Some of the remains are in an advanced state of decay, so authorities have been unable to confirm identities or nationalities.

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