Migori Governor Okoth Obado is set to be arraigned on Monday over the murder of Rongo University student Sharon Otieno.
Police say Mr Obado will spend the weekend at Gigiri Police Station.
The Governor was arrested earlier Friday and questioned on the murder of Ms Otieno at the headquarters of the Directorate of Criminal Investigations (DCI) on Kiambu Road in Nairobi.
Sources told the Nation that he was to record a statement.
Mr Obado was apprehended a day after detectives confirmed that Ms Otieno’s unborn baby was his.
The university student was seven months pregnant.