AS the country's national high school examinations began Monday, students claimed they were using technology and bribes to get an edge over their peers, despite education officials saying that they would crack down on exam cheats.

Hok Keasi Nuon, a home economics teacher at Chea Sim Sammaki High School and a member of the Ministry of Education's examination committee at the Chaktomuk High School examination site, said Monday that invigilators performed their roles properly.

"We checked and collected many cheat sheets and hand phones from the exam participants," she said, but added that she did not know what happened once the students were in the exam rooms.

Indeed, students said they found it relatively easy to elude or buy off the exam overseers.

"I told my sister the questions by phone, and after a few minutes she told me the answers," said Theary, a student doing his exams at Preah Sisowath High School.

"I used the phone in silent mode connected with the Bluetooth earphone, and when I talked to my sister I pretended to be thinking about the question and answer."

He added: "I put the earphone on my cufflink and my phone on my right leg."

Lach Sreymau, 18, said that her cheat sheets and mobile phone were confiscated when she walked into the exam room. But she said there were still ways to game the system.

"[Students] can share their answers with each other in the examination room because we collected some money for the invigilators," she said.

Satya Soeurn, a student who failed the high school exams last year, also said that he paid each invigilator 5,000 riels (US$1.20) to allow them to bring in cheat sheets during the exams.

But education officials said they did not believe the cheating was widespread.

Rong Chhun, president of the Cambodian Independent Teachers Association, said Monday that the first day of exams went smoothly, and that police made sure students didn't try to bend the rules.

"We observed the examination for the whole day, and we didn't see any irregularities - but we heard some students could be using phones to contact [others]," he said.