Acting on a tip-off, a special unit of the DRI laid a trap and seized the truck carrying a consignment of 751.6 kg ganja from Andhra Pradesh for delivery to a client in Hajipur, the district headquarters of Vaishali district, the sources said.
The contraband was hidden in a special cavity in the vehicle, they said.
Mewa Singh from Punjab, who was travelling in the truck, was arrested.
The seized contraband was valued at Rs 37.58 lakh in the market, the sources said.