Four alleged exam imposters are facing potential prison time after they attempted to steal a better score on a highly selective Korean proficiency exam this weekend.

According to Kampong Chhnang police, the four suspects were hired for up to $1,000 each to sit the test, which is one of several eligibility requirements for Cambodians hoping to secure work in South Korea.

The imposters were caught before they were able to enter the test centre, however, as their IDs and fingerprints did not match up with the real candidates’ information, police said.

After the imposters were arrested, they admitted to taking part in a racket organised by a woman in Phnom Penh named Chheon Mao who helped match proficient Korean speakers with test-takers lacking confidence in their language skills, police said. The test candidates agreed to pay between $500 and $1,000 in exchange for a passing mark on the highly competitive test. Over 51,000 applicants signed up for the exam, but only the top 4,000 scorers will be allowed to pass.

The four male suspects, Sin Vimean, 32; Chhuos Vanna, 30; Phun Sophoin, 25; and Suon Kosal, 25, are currently being held at the Kampong Chhnang provincial police station until they are sent to court.

“Based on the testimony, the leader [of the scheme] lives in Russey Keo district … but we do not know whether or not it is her real address. Now police are preparing the case and investigating to arrest the leader,” said deputy Kampong Chhnang town police chief Chhay Khem Roath.

The real test candidates have not been arrested or contacted yet by police, Roath said.