Three police officers and a taxi driver have been arrested by the police in connection with the disappearance of a Meru-based doctor.
The suspected officers are based at Riruta and Kabete police stations.
Detectives privy to the incident said the officers were arrested as they were among the last people to speak to the missing doctor Alex Omariba.
Omariba was reported missing on August 26.
The four were arrested by officers from the Special Crime Prevention Unit over the weekend and are expected at the Kibera law courts on Monday morning.
The suspects will not be required to plead to any charges as the investigators intend to seek the court's authority to detain the suspects until investigations are complete.
Sources said Omariba was lured to the city centre by people claiming to be police officers and was last seen being bundled into a waiting taxi on Moi Avenue.
The incident comes barely two months after the abduction and murder of human rights lawyer Willie Kimani, and his client Josephat Mwenda and their taxi driver Joseph Muiruri.
The three went missing in July as they drove along Mombasa Road from the Mavoko law courts.
The were later discovered floating in a river at Ol-donyo Sabuk.