Baringo County Assembly Speaker William Kamket was on Friday arrested in Ol Donyo Sabuk, Machakos County while identifying the body of slain Churo Amaya Ward MCA Thomas Minito.
He was arrested alongside four other individuals who are yet to be named.
The reason for the arrests, however, remains unclear.
On Thursday, Mr Kamket had been grilled and released by officers from the Directorate of Criminal Investigations (DCI) at Kabarnet Police Station over allegations of his involvement in brokering banditry in Tiaty, Baringo.
The late Minito's body was found dumped in a river in Matungulu Sub County after he had been reported missing under mysterious circumstances.
Meanwhile, Police have said in a statement that they have launched forensic investigations into the death of the MCA.
They also appealed to members of the public to come forth and assist with any information that may aid police investigations.