Police on Sunday impounded a vehicle at the Taveta One Stop Border Post after undeclared arms and ammunition were found in it.
Taveta Sub-County commander Lawrence Marwa said the vehicle belonged to a South African courier service and the consignment to AANDA Sales and Services Limited.
Mr Marwa said the items, destined for Nairobi, had been concealed as household goods.
"The verification supervisor at the customs department at the [OSBP] realised the consignment was not of household items as alleged. That prompted further verification," he said.
Mr Marwa said no arrests were made but the driver and clearing agents were helping police with investigations.
"The company allegedly has a licence to import and sell such arms and ammunition in the country. We are waiting to verify the licences before releasing the vehicle," he said.
The vehicle was taken to the OSBP yard.