- Mr Njogu said they suspected that the materials were intended to be used to stuff ballot boxes.
The announcement of results for various elective seats in Kilgoris constituency, Narok County, was marred by delays and arrests, which almost crippled the process.
Tallying was temporarily halted after a presiding officer, his deputy and a police officer were arrested with ballot papers in a house.
Mr George Akumu, the presiding officer for Endoinyo Nkopit polling station and his deputy, Ms Sarah Yiamat Leperon, were seized in Milimani estate in Kilgoris town.
Trans Mara West director of criminal investigations David Njogu said the two were in the company of Mr Pius Otieno, an Administration police officer.
Mr Njogu said they suspected that the materials were intended to be used to stuff ballot boxes before sending them for tallying.
"Voting had ended at the polling centre and the materials were then dispatched to the tallying centre.
"But while on the way the presiding officer diverted them to his house for unknown reasons," Mr Njogu said.
Among the materials impounded were six ballot boxes and an unknown number of ballot papers.
Mr Njogu said that most of the ballot materials were marked.