Customs officers seized 29kg of ketamine, the largest seizure of the drug this year, at the KL International Airport arrival hall yesterday.

The drug was found in the luggage of a 47-year-old passenger who had arrived from India.

The drugs, with a street value of RM1.15mil, were concealed in a metal box that looked like an air-conditioning unit.

The suspect, a Malaysian from Balakong who had earlier disembarked from a Thai Airways flight from Hyderabad via Bangkok, was arrested at 12.50pm after Customs suspected something amiss.

Customs deputy director-general (prevention) Datuk Mardina Alwi said that upon inspecting the Malaysian's luggage they found the "air-conditioning unit" to be a box containing black bags filled with a white crystalline powder.

The substance was later found to be ketamine.

Mardina said this was the 24th ketamine case solved by the department this year.

"We have cracked more ketamine-related cases to date compared with only 13 such cases throughout last year," she said.

Mardina said that this was the first case in which the drug was found hidden in a fake air-conditioning unit. Drugs smuggled on board flights were often concealed in smaller electrical items.

The suspect has been detained under the Dangerous Drugs Act and faces the mandatory death penalty upon conviction.