The body of the missing Meru nurse has been traced to Machakos mortuary.
The body had visible injuries on the neck and arms an indication of torture prior to his death.
Omariba, a former nurse at a mission hospital in Meru, went missing in mysterious circumstances in Nairobi on August 21.
He is reported to have been lured to Nairobi by a woman who promised to help him grow his business in Meru.
On Monday, three police officers and a taxi driver have since been arrested in connection with his disappearance.
Head of Special Crime Prevention Unit Noah Katumo said police traced the body at the mortuary after receiving information from the public.
He declined to comment further, but sources at mortuary said the body booked as unknown was brought in by the police on August 22.
They said police found Omariba’s remains in Salama area in Makueni county.
The incident comes shortly after the torture and murder of human rights lawyer Willie Kimani, his client Josephat Mwendwa and their taxi driver, Joseph Muiruri.
The three are said to have gone missing after having last been seen by security agents.
Four administration police officers have been linked to their murder and torture and are currently undergoing trial.