The passenger had arrived from Sharjah by an Air India flight, they said.
Customs Commissioner Sumit Kumar said officers seized some material, suspected to be narcotics, concealed in a consignment meant for export to Kuala Lumpur, from the Thiruvananthapuram Air Cargo Complex.
The material, concealed in plastic pouches in six plastic folders were opened on suspicion and found to contain a white crystalline powdery substance.
CISF and state Excise department personnel, who were called in, tested samples, which showed that the material could be narcotic drugs, he added.