The five were carrying a white powder from Tanzania when they were arrested at a roadblock.
Police say they are yet to know the nature of the drugs and if the powder is a narcotic.
Head of anti- narcotics unit Hamis Masa says they are detaining the five for further investigations.
"We arrested them with a powder that we think is a drug. The powder has been sent to government chemists for further tests and analysis," said Masa.
Other officials said the former MP and Akinyi have been on their radar of drug trafficking.
They were being detained at the Muthaiga Police
