Director of Public Prosecutions (DPP) Noordin Haji has directed Inspector General of Police Hillary Mutyambai to investigate the utterances by Meru Senator Mithika Linturi in Eldoret on Saturday.
In a letter seen by K24 Digital, DPP said the remarks could incite feelings of hatred.
"My attention has been drawn to a video circulating on social media platforms portraying Mithika Linturi alledgely addressing a crowd and stating that 'watu wa Uasin Gishu musicheze na Kenya, na kile nawaomba ni kwamba madoadoa yale mulionayo hapa muweze kuondoa'," DPP wrote.
Several leaders allied to President Uhuru Kenyatta and ODM leader Raila Odinga have since condemned the remarks.
Nakuru Governor Lee Kinyanjui said the utterances could threaten peace among communities living in the Rift Valley region.
"We may have our political differences but peaceful coexistence is a common asset for all irrespective of political orientation.
"The right to live, work or invest in any part of the country is not a favour from politicians, but a constitutional right," Kinyanjui said.
However, Senator Linturi has said people are spinning what he said, insisting that he stands by his statement.
"My message was clear, I don't owe anybody any explaination.Whoever does not support the DP @WilliamsRuto in the region should not be elected," Linturi wrote on his Twitter account.