Detectives of the Ethics and Anti-Corruption Authority (EACC) on Tuesday evening arrested Migori County Secretary Christopher Rusana over abuse of office.
EACC's South Nyanza Region Director, David Kangara, said Mr Rusana was taken to Migori Police Station.
“The Director of Public Prosecution [Noordin Haji] gave us the go-ahead to arrest him We will give more details later,” said Mr Kangara.
He said the secretary will be interrogated on Wednesday and arraigned on Thursday.
Mr Rusana is now in a long list of Migori officials on the EACC's radar over claims of abuse of office and corruption.
Governor Okoth Obado, one of the officials under investigation, is accused of using proxies, including his relatives, to siphon Sh2 billion from the coffers of the county government, according to an affidavit filed in court by the anti-corruption watchdog.
The EACC has been looking into allegations that Mr Obado used his position to steal public funds through companies registered by his relatives.
In a period of three years, the newly registered companies had transacted Sh1, 971,179,180 in deals exclusively from the county government, which was glaringly disproportionate to their known legitimate sources of income.
“The commission received credible information that a few persons well known to be proxies of the governor, registered several companies for the purpose of fraudulent acquisition of public funds through fictitious contracts,” the EACC says.