Thirteen people were arrested in Nyamira County over exam cheating allegations.
Police arrested six private candidates sitting for the KCSE in Nyamira South while they were preparing for the tests.
According to reports, the candidates were found with suspicious materials in the examination centre.
Nyamira South Sub-county Police Commander Moses Kirong confirmed the incident adding that the suspects are in custody.
Commander Kirong said investigations were being carried out and warned others who might be tempted to cheat.
The adult education learners who were registered as private candidates were found with questions and answer materials. Police said the exams were related to the Chemistry practical exam.
The learners were doing their exams at the Nyamira Town centre where a total of eight candidates were taking their exams.
Yesterday Education CS Prof said 15 people among them a university student have been arrested over exam irregularities in Kenya.
CS Magoha noted that 8 KCSE candidates were found with mobile phones. He warned of a plan by some schools to use university students to sit the KCSE exams.
He told journalists that 15 phones confiscated and further warned parents against buying fake papers that are circulating in the market.
"There are people selling fake papers. Parents, do not be duped to buy these papers. There is no exam that has leaked," he said.