SSB Assistant Commandant Suraj Kumar said the seized contraband was kept in 20 sacks and its market price is estimated to be around Rs 3 lakh.
The seizure was a result of enhanced vigil in the wake of Republic Day.
"We had received intelligence inputs that smugglers had brought a consignment of betelnut from Nepal. We tracked them to Raxaul and seized it in the train. The consignment was taken out from the train at Sitamarhi railway station," Kumar said.
Officials said the seized betelnut could have been ferried from China en route Nepal for India.