The sleuths have arrested a man who has been in hiding for a week since he defiled his 6-year-old daughter in Megogo village, Marani, Kisii county.
He was arrested on Sunday following outrage from Kenyans and will be arraigned on Monday.
He was arrested by detectives from the Crime Research and Intelligence Bureau and their Kisii counterparts, at his hideout in Kongasis, Kiambogo in Nakuru County.
Julius Ogamba Ongera is alleged to have lured her daughter into a thicket where he committed the beastly act.
The detectives said that the suspect went ahead to threaten his wife with dire consequences if she dared to report the matter to the police.
The girl was found in a coffee farm by villagers writhing in pain and rushed to Marani Sub-County hospital before she was transferred to Kisii Teaching and Referral Hospital for treatment. The suspect immediately went into hiding after detectives launched his manhunt.
County Woman Rep Janet Ongera and Women nominees from Kisii County Assembly described the incident as horrible and a grave moral sin.
They urged security agencies to speed up the 'hunt and quick prosecution of the suspect'
Kisii Governor James Ongwae offered to pay her medical bills.
