Detectives from the anti-corruption watchdog on Thursday morning raided the homes of Kiambu Governor Ferdinand Waititu in Runda and Garden Estate, Nairobi.
Tens of officers arrived at the residence a few minutes after 5am and started a search for files and documents.
The detectives who are investigating alleged corruption in the county that borders the capital Nairobi were searching for documents relating to contracts issued by Mr Waititu's administration.
The outspoken governor, popularly known as Baba Yao, is under the EACC spotlight over alleged corruption in a number of his county programmes, including Kaa Sober, which was aimed at rehabilitating alcoholics.
Sources told the Nation that 15 other officials of the county government are targeted in the ongoing investigations.
The Kiambu governor, who has been in the news recently over questionable expenditure at the county in the last financial year, is facing allegations of procurement irregularities and unexplained expenditures.
Mr Waititu has also been questioned over his recent property acquisitions, including that of a building located within Nairobi's central business district.
But in videos posted online by his supporters, Mr Waititu claims the investigations are politically influenced.
He says he has worked hard to acquire his property.
And as some officers ransacked Mr Waititu's Runda home, a separate team was camping at another residence at Bellcrest Gardens on Githunguri Road in Kileleshwa.
It is suspected that the posh home belongs to one of the officers targeted in the investigations that are likely to result in arrests.
The raid comes as EACC intensifies the fight against corruption in the devolved units.
On Wednesday, detectives grilled Murang'a Governor Mwangi wa Iria at the EACC office in Nyeri over the controversial purchase of a 10-acre piece of land in Kabati at an alleged inflated price of Sh390 million. The interrogation lasted three hours with Mr Wa Iria leaving shortly after 7:30pm.