However, these instructions only direct the centre managers to prepare some solutions and other reagents or instruments in parcels marked confidential.
"These advance instructions do not come with questions that candidates will be given," said the CEO, adding that some principals share the instructions with people misleading the masses.
He said there is no other way other than to send advance instructions to ask schools to prepare for the practicals.
He defended the council against claims of weaponisation of the examination, with legislators and some parents taking issue with the deployment of heavy security around examination areas.
Njeng'ere said the multi-agency approach to examination was introduced in the 2016 reforms to bring back the credibility of national examinations.
Machogu and Dr Kipsang said the ministry proposes amendments to the Knec Act of 2012 to include the 2016 reforms, saying most of the things brought about by the reforms are yet to be anchored in law.
According to the Act, exam papers are supposed to be kept in police armories.
However, after the 2016 reforms, the containers where introduced to keep exam papers.
Marakwet West MP Timothy Kipchumba accused Knec of becoming law unto itself and suggested the establishment of a Kenya National Examination Regulatory Authority to keep the exam body in check.
But Njeng'ere said the council had not done anything outside the law and hence cannot be said to have become a law unto itself.
"We have not at any point exceeded the powers given to us in law," he noted.
He said the council was financially constrained and called on the MPs to lobby for more budget allocation.
"Before 2016, Knec used to collect examination fees from learners, and these were used for administration of the exams. However, this was scrapped, and the government took over the fees.