The suspects' vehicles were taken to the DCI headquarters in Nairobi.
Officers at the Muthaiga Police Station are detaining three people accused of trafficking bhang.
Among the suspects is a General Service Unit (GSU) officer identified as police constable Kebeno Aminga Duke,
Others are Wycliffe Omwenga Mokaya (30) and Allan Machogu Nyarundia (25).
According to the Directorate of Criminal Investigations (DCI), the suspects were intercepted in the Karai area along the Nakuru-Nairobi highway on Friday, November 8.
"Acting on a tip-off, anti-narcotics detectives intercepted the two cars - Toyota Noah Reg No. KDB 190A and Toyota Fielder Reg No. KDL 731V - seizing the drugs weighing 50kg that were concealed in gunny bags," the DCI said.
The suspects' vehicles were driven to the DCI headquarters along Kiambu Road, Nairobi, as they await arraignment.
This comes months after detectives attached to the DCI arrested a Kenya Defence Forces (KDF) soldier in connection with drug trafficking in Mombasa.
The army man was arrested in the company of a juvenile.
The DCI, in a statement, said the ambush in several Mombasa localities was undertaken by a multi-agency team comprising law enforcers and other government and non-government agencies in Operation Usalama.
The officers targeted dens in other areas, such as the Kengeleni, Magodoroni, Shanzu, and Kisumu Ndogo areas.
The KDF soldier was found to be in possession of Heroin, Marijuana and Diazepam.
They were booked into police custody ahead of their arraignment.