Kisii Central police OCPD Symon Gababa was found dead in his car outside staff quarters in Milimani area.
Officers investigating the death of Gababa said the cause of death is yet to be established.
Earlier this month, Huruma OCS Simon Ndeti was found dead in his house where he lived alone.
Pangani deputy police boss William Sirego said the officer was discovered dead at the house in Huruma.
Sirego said the officer had earlier visited Nairobi West Hospital where he was treated and returned to his house.
Ndeti had been recently transferred to the current posting from Karatina police station in Nyeri county, where he had served in the same capacity.