The cash was recovered from a vehicle near Chandni Chowk area, Muzaffarpur Senior Superintendent of Police Manoj Kumar said.
The exercise was undertaken after an alert sounded by the Income Tax Department regarding huge cash being transferred between Patna and Raxaul.
Those arrested include one from Patna and two from Motihari in East Champaran district. All three were being interrogated at Yahyapur police station.
It is yet to be ascertained whether the cash has anything to do with Lok Sabha polls.