The principal of an education centre and three of her tutors schemed to help six students cheat during the 2016 O-level examinations.
The students, who are Chinese nationals and were aged between 17 and 20 at the time, smuggled mobile phones and Bluetooth devices into exam halls in Singapore.
Answers were then whispered to them through their skin-coloured earphones. The ruse involved exam papers for English and mathematics, among other subjects.
Yesterday, District Judge Chay Yuen Fatt convicted three of the offenders after a trial.
Principal of the now-defunct Zeus Education Centre Poh Yuan Nie, 54, and two tutors - her niece Fiona Poh Min, 33, and Feng Riwen, 28, were each found guilty of 27 counts of cheating.
A fourth offender, former tutor Tan Jia Yan, then 33, was sentenced to three years' jail in April last year over her role in the ruse.
Feng is a Chinese national, while the others are Singaporeans.
The prosecutors stated in their submissions that Poh Yuan Nie, also known as Pony, was paid $8,000 a student by a Chinese national, Mr Dong Xin, to provide tuition for the students to help them pass the exams and enter local polytechnics.
Deputy Public Prosecutors Vadivalagan Shanmuga and Cheng Yuxi had earlier told the court that a few hours before each exam, Fiona Poh, Tan and Feng helped to attach communication devices on the students.
The court heard that the students then sat the exams with these devices taped to their bodies and carefully concealed by their clothes.
The prosecutors added: "During the examinations, Jia Yan's role was mainly to sit the examinations as a private candidate and use the FaceTime application on her phone to present a live stream of the question papers to the co-accused stationed at the tuition centre.
"The others worked on the questions streamed to them. Riwen (and others) then called the students to read the answers to them. Pony oversaw the entire process."
The prosecutors stated that this criminal set-up succeeded for three papers, from Oct 19 to 21, 2016.
But it fell apart on Oct 24 that year when an alert invigilator heard "unusual electronic transmissions and voices" coming from one of the students.
After the exam, the student was taken to an office, where he handed over devices, including Bluetooth receivers and an earpiece.
Poh Yuan Nie is represented by lawyer Peter Fernando. He argued during the trial that there was no evidence that his client and the three others had a "legal obligation" to inform the Singapore Examinations and Assessment Board that the students would be receiving help from others while they were taking their papers.
The prosecutors said this argument was misconceived, adding: "The students were clearly governed by the rules of the GCE O-level examinations - including a rule that provided that the students were not to bring into the examination venue any unauthorised materials or electronic devices."
The trio are expected to be sentenced on Aug 21.
