The seizure was carried out by the Economic Offences Unit (EOU) and Special Task Force of the Bihar Police.
"The gang procured huge consignments of ganja from Odisha. It was brought to Bihar in trucks and smaller vehicles for further distribution," EOU Inspector General Praveen Vashista said.
Nine members of the gang, including its kingpin Ram Vivek Singh were arrested, Vashista said.
"Singh is a notorious name in the field of ganja smuggling. The narcotic consignment was hidden in compartments inside a small truck and an SUV. The vehicles were seized," he said.
Sources said that the gang was in touch with Maoist sympathisers in Odisha, who cultivated ganja to fund their activities.