EACC detectives raided Kiambu Governor Ferdinand Waititu’s homes on Thursday to search for evidence linking him to the irregular award of a Sh588 million tender.
EACC CEO Twalib Mbarak, in a statement, said preliminary findings reveal that contractors paid senior county officials, their companies and their relatives.
The governor has also been accused of fraudulent acquisition of public funds, conflict of interest and money laundering.
EACC boss said that valuable evidence relevant to the ongoing investigations was recovered.
The suspects are still being interrogated at EACC headquarters.
Waititu was arrested after more than six hours of interrogation following a dawn raid by the detectives in his Runda and Garden Estate homes in Nairobi.
Some 15 other county officials are also under the EACC radar over the matter.
Earlier this month, the Kiambu County Government presented the Senate with a financial statement showing Waititu may have allocated budgets for functions unrelated to Kiambu.
