Matungu Member of Parliament Justus Murunga has surrendered to police, after Kakamega Senator Cleophas Malala and former Sports Cabinet Secretary Rashid Echesa were arrested by detectives from the DCI.
The legislator becomes the fourth person to be arrested over links to the Matungu killings that have seen 20 people lose their lives.
Senator Malala, Echesa and Mayoni MCA Libinus Oduor were arrested on Friday as police intensify their crackdown on a killer gang.
On Thursday, Interior CS Fred Matiangi visited Matungu sub-county and promised a security crackdown following the wave of killings that claimed 20 lives, in two months.
CS Fred Matiang'i began his visit in Matungu, where 13 villagers were murdered by criminal gangs in the past month, and later toured Kilingili where six watchmen were killed at the local market.
Two others were murdered at Mulwanda market in Khwisero.