Detectives are hunting for a tenant of a house where 92kg heroin was seized on Thursday.
The drugs with a street value estimated at Sh300 million were found in Kikambala, Kilifi county.
Reports indicate the tenant, believed to be a woman, has lived in the house for only for a few months.
A source told the police from Mombasa, who were acting on a tipoff, seized the narcotics.
Mombasa police commandant Johnstone Ipara confirmed that drugs had been found, but declined to divulge more details.
The heroin was taken to Mombasa police headquarters for examination by narcotic experts.