A 42-year-old man was arrested with opium (karupp) worth Rs 40 lakh at Palakkad on Tuesday.
Afsal, a native of Othungode, was arrested while awaiting customers near the Chandra Nagar over-bridge.
Karupp is a product extracted from the milk of poppy seeds and is regarded as a highly potent narcotic substance.
District Police Chief Viswanadh R said in a press release that his customers were mostly daily-wage workers, who were addicted to drugs.
According to the local police, Afsal got the contraband item through intermediaries from Rajasthan.
"We have got information about the source and investigation will focus on that," said Viswanadh.
A squad of Palakkad District Anti-Narcotics Special Action Force (DANSAF) and the Kasaba Police had made the arrest.
