Those arrested include the Principal of Gatuanyaga secondary School Joseph Weru, an examination Supervisor Lucy Gathiru and Sergeant Laban Kinyua Murage.
Police said the three were picked up after the Chemistry papers were found to have been tampered with, contrary to regulations set out by the Kenya National Examinations Council (KNEC).
Kieni East Police chief Michael Mbaluku said the three were arraigned at the Nanyuki Law courts on Monday afternoon but it was not immediately clear what charges they faced.
This year’s national examinations were administered amid tight security, due to the introduction of new tough measures to curb cheating.
It involved having secure containers at centres across the country which were guarded by police officers, with strict instructions on their opening under the supervision of centre managers.
About 577,000 candidates are seating for this year’s KCSE exams.
Education Cabinet Secretary Fred Matiang’i who supervised the opening examination containers in parts of Murang’a has warned of tough action on anyone found contravening the regulations governing the process.
Under the new KNEC regulations, supervisors and invigilators were vetted by the Teachers Service Commission (TSC) to ensure they have no criminal record before they were cleared to take part.
To stop teachers from colluding with candidates to cheat, Matiang’i further directed that head teachers and principals be in charge of examination centers with the help of supervisors.
The ministry also banned communication between candidates and any other people who might be out to influence.
Cheating cases attract stiff penalties, with those impersonating candidates would be fined Sh2 million or risk a two-year jail term or both.
Past national examinations have been characterized by massive rigging.
On Monday, KNEC Chairman Professor George Magoha led a team from his office on impromptu tours in Nakuru schools and examination centres to ensure all went well.
In Mombasa, Coast Regional Coordinator Nelson Marwa told journalists that they are not leaving anything to chance in ensuring that examinations are undertaken as per the regulations from the ministry and KNEC.
“Systems have been put in place, security is very tight. No exams leaves the container without escort, no exams comes to the container without escort and no exams go to Nairobi without escort. There is tight security and any interference in between will mean the officers go home regardless of who you are,” he stated.
Marwa stated that more police officers have also been deployed to guard schools during the examination period.