South Korea’s top court has upheld the conviction of a local man for kidnapping Korean tourists in the Philippines, court officials said Sunday.

The 20-year-old kidnapper, only identified by his surname Kim, was sentenced to 10 years in prison for conspiring with four Koreans to abduct nine Koreans who were on vacation in the Philippines between November 2010 and September 2011.

“Kim, along with his accomplices, meticulously planned to lure the tourists. The method of his crime was cruel as he had threatened the victims using guns and knives,” the Supreme Court said in its ruling.

A series of high-profile abduction cases in the Southeast Asian country drew heavy media attention as the fate of one of the kidnapping victims, Hong Seok-dong, is still unknown.

Hong, the 30-year-old Korean tourist, was abducted by the kidnapping ring in the Philippine capital city of Manila in September 2011. Earlier this year, Hong’s father committed suicide after allegedly making a desperate appeal to the Seoul government to help find the son.

“(The defendants) extorted a large sum of money from the victims and it is not yet clear whether one of the victims is still alive or not,” the court added.

Kim and another South Korean tour guide surnamed Choi extorted a total of 220 million won ($200,800) from families of the victims, they said.

Choi, suspected to have masterminded the entire kidnapping plan, was arrested by local law enforcement authorities in the Philippines in November.

The South Korean government has since been making various efforts and demanding the Philippines swiftly repatriate Choi to South Korea. (Yonhap News)