Radio receiver devices and other communication equipment were allegedly involved in massive nation-wide cheating in the national police entrance exam in Thailand.
The scam came to light when a short-wave radio signal receiver was found on a latecomer who was searched.
Bangkok Post reported that the receivers were modified to receive vibrating signals from a gang which dictated to them the correct answers for the multiple choice tests.
Soon, other applicants, both men and women, were caught and confessed to having hidden the receivers in and around their private parts.
Other testing sites were alerted and 23 more applicants were detained after being found with similar radio receiver devices. The exam, which was held on Sunday, has been cancelled.
The discovery led to a search of a hotel where the applicants who were arrested said they were staying along with some people who orchestrated the scam.
At the hotel, five suspects, including a woman whose husband is a police officer, were arrested and radio signal transmitters seized. The husband was then arrested in Si Sa Ket province and about 10.5 million baht (S$425,590) in cash was seized from him.
The police are investigating if any of their officials were involved in the scam which ran into millions of baht, reported The Nation.
Provincial Police Region 3 chief Phanu Kerdlarppol told Bangkok Post: "I believe some insiders must have colluded with the gang.
"There were up to eight different test papers...it was impossible that the tests were leaked without the insiders' help."
One of the suspects allegedly told police the eight versions of the tests were bought for three million baht each a few hours before the exam began, because the test papers were printed only that morning to prevent a leak.
After that, a team worked on the tests before sending out radio signals to the receivers.
All eight tests contained the same questions but in different orders.
The police believe more people, other than those arrested, were involved because those sending signals to the vibrating devices would have had to be within a 300m radius.
Bangkok Post reported five suspects testified that the network had been operating for a long time and had leaked exam papers at other state agencies.
This article was first published in The New Paper.