Adul said he needed a week to screen for culpable applicants before a list of innocent successful candidates would be passed for criminal background checks before the test results are announced on January 30.

Out of 52 wanted persons in the case, 37 students have testified to police investigators while five asked for postponements due to being preoccupied with university exams or trips abroad. Another 10 failed to show up.

Adul said that Bangkok city regulation enforcement officer Jiraphot Plaidoung, who surrendered last week and allegedly confessed to arranging exam cheating in exchange for hefty fees, had been released on bail of Bt150,000.

He added that Jiraphot had provided useful information leading to his release on bail, and police were now looking to arrest up to three exam-cheating groups, each comprising between five and 10 members.