Police are investigating the circumstances under which Meru Governor Peter Munya lost his gun at his Nairobi home.
The Council of Governors chairman told police he had been away and when he returned to his Garden estate house, the pistol, which was loaded with 14 bullets, was missing. The weapon was in a safe, which is also missing together with crucial documents.
It is believed the incident happened as Munya, a licensed gun holder, presided over the devolution conference in Naivasha last week.
Police suspect one of the county chief's workers may have stolen the weapon.
Mr Munya realised the weapon was missing on Saturday morning and reported to police.
Kasarani police boss Robinson Mboloi said they were investigating the matter, adding that: "We don't know when it was stolen but we are following various leads."
Some of Munya's employees have already recorded statements. Some of them had access to the room where the gun had been kept.
Cases of safe keeping of guns have raised concern, leading to calls for proper and strict regulations. Two weeks ago, a house help stole her employer's weapon in Lavington together with a safe.
The weapon and safe were three days later recovered in Kawangware and three suspects arrested. The woman is yet to be arrested.
Last month, a university student used his father's gun to commit suicide in Spring Valley, Nairobi. It is not clear how the student accessed the weapon that was in his father's bedroom. On Wednesday night, businessman Paul Kobia was arrested after he shot in the air in a confrontation in Kilimani.
There are 10,000 licensed firearm holders in the country. Authorities are in the process of implementing various reforms aimed at addressing misuse of licensed guns. The Firearms Licensing Board has been cancelling permits issued to those who have misused their weapons.
Before one is allowed to own a gun, he is required to apply through an officer commanding station, who forwards the application to the officer commanding police division who then convenes a meeting of the district intelligence and security officers for review before it is sent to the county commander for approval.
Officials have to inspect the safe where the weapon is supposed to be kept.