Migori Governor Okoth Obado is currently being interrogated at the DCI Headquarters in Nairobi over the murder of Rongo University student Sharon Otieno.
The move comes days after detectives promised high profile arrests between Friday and Monday.
Obado has been adversely mentioned in the murder which left the nation shocked.
A DNA test revealed that the baby Sharon was carrying had been fathered by the Migori County chief.
Also behind bars are six suspects who are closely related to Obado.
From his PA Michael Oyamo to a member of his security detail.
A police source said they are trying to unmask those who wanted the university girl to abort the baby as that can be behind the motive to murder her.