EXPOSITION PARK (CBSLA.com) — A former University of Southern California professor and author has become the 500th person to be added to the FBI’s Ten Most Wanted Fugitives list, it was announced Monday.

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Walter Lee Williams, 64, is wanted for the alleged sexual exploitation of children and for traveling abroad for the purpose of engaging in illicit sexual acts with children.

He is accused of traveling to the Philippines to engage in sex acts with two 14-year-old boys, according to KNX1070’s Claudia Peschuitta.

Authorities say a tip from an adult student prompted a joint investigation by the LAPD and the FBI that found Williams used his academic research as a guise to target primarily underage boys in the Philippines, Indonesia, Polynesia and Thailand.

Williams, who was affiliated with Buddhist Universal Association, has traveled extensively throughout South East Asia. He disappeared after he was interviewed by the Los Angeles Police Department in 2011.

A federal arrest warrant was issued for him on April 30 after he was charged with sexual exploitation of children, travel with intent to engage in illicit sexual conduct, engaging in illicit sexual conduct in foreign places, and criminal forfeiture, according to the FBI.

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Williams taught anthropology, history and gender studies at USC reportedly until 2011, although the university would not confirm his start or leave dates. The FBI said there is no evidence that illegal activities were associated with USC or took place on campus.

Williams’ blog highlights his travel and spiritual interests, as well as books he has written and academic honors he received.

“I’m shocked,” one student said. “Typically, you wouldn’t associate USC with this sort of a thing.”

“The teachers that you are entrusting your children’s education to, you hope aren’t on the FBI’s most wanted list,” parent Claire Banks told KCAL9’s Suraya Fadel.

The FBI is offering a reward of up to $100,000 for information leading to Williams’ arrest and conviction.

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“It is entirely possible that he is living comfortably, and that he has the means to travel and to continue to exploit young children. For that reason is among the most wanted in the FBI in the United States,” said Bill Lewis, assistant agent in charge of the FBI’s Los Angeles field office.