Detectives from the anti-graft agency raided Nyamira County government offices over the controversial hiring of workers for one of the departments.
The officers ransacked the offices of the county secretary, County Public Service Board and youth affairs.
The 55 employees were posted in the department of Sport, Youths and Gender late last year.
The operation took more than five hours, with police officers stationed at the entrances and journalists barred from accessing the premises.
However, county Secretary Eric Ochana was not in the office and could not be reached by phone.
Chairman Peter Nyakundi was questioned and the chief officer in the youth department, Thomas Geni, presented documents relating to the hires to the detectives.
Abraham Kemboi, the Ethics and Anti-Corruption Commission’s regional coordinator for Kisii, said the investigation was prompted by a public outcry that followed the recruitment and that also led to the dismissal of the new employees.
Mr Kemboi added that there were claims that the recruits had submitted fake certificates and others offered bribes.
“We are also investigating claims that some of the applicants had used fake documents in applying jobs in the ministry in question,” Mr Kemboi said by phone.
The detectives took away computers and files related to the recruitment.
In December, Public Service Board members, senior officers at the department of gender and members of the county assembly’s sports, youth and gender committee were questioned over the alleged misconduct.