The directorate of criminal investigations has taken over the case in which a Kanu candidate's children were killed in cold blood.
Kapsoya MCA candidate James Ratemo Nyambane's three children had been missing before they were found dead.
Eldoret East OCPD Adamson Furaha said officers from the DCI office had officially taken up the matter and would continue with the investigations.
"The matter is now with officers from the DCIO and will be assisted by officers from Nairobi who will work together to hasten the investigations," said Mr Furaha.
He added that police had changed the charges against the suspect from abduction to murder, since it had been established that the children were murdered some where else before being dumped in River Nzoia, along the Trans Nzoia and Uasin Gishu border.
Mr Nyambane's brother Enoch Onsanse, 26, is the key suspect in the case and is expected to take a plea in an Eldoret court on Tuesday.
Witnesses have alleged that Mr Onsanse was the last person seen with the three children on the Saturday before they disappeared only for their bodies to be found dumped in River Nzoia near Moi's Bridge on Tuesday last week.
The family wants detectives to speed up investigations into what led to the murder of Clifford Nyambane, 6, Taniy Nyamweya, 5, and Glen Ongaki, 3.
They have called on the public to stop speculations in the matter and allow police to investigate every possible lead.
Following the murder two MPs, Alfred Keter (Nandi Hills) and his Kapseret's Oscar Sudi visited the family at their Kapsoya home in Eldoret over the weekend.
The lawmakers said such an incident had the potential of fuelling fear among Kenyans from different backgrounds bearing in mind that the country is in an electioneering period.
At the same time, Uasin Gishu senatorial aspirant on a Jubilee ticket, Prof Margaret Kamar, asked the media and social media users to stop speculating on what led to the killings.
The family's spokesman, Mr Charles Nyamweya, said the family feels the killings could have involved more than one person hence investigations must go deeper in order to bring to book all suspects.
Kanu coordinator in Rift Valley Jonathan Bii questioned the timing of the killings since the children's father is vying on a Kanu ticket. However, Prof Kamar asked politicians to stop associating the murder with politics and allow investigators to complete their work.