The three, who included a former Head Constable of the force, were possessing the US Dollar 1980 illegally.
Besides the "one million dollar" note, the three were carrying a certificate authenticating it and two blocks for manufacturing the note, the officials said.
According to the website of US department of the treasury, the present denominations of the currency in production are Dollar 1, Dollar 2, Dollar 5, Dollar 10, Dollar 20, Dollar 50 and Dollar 100.
One of the apprehended person is a former Head Constable of BSF 68 battalion identified as Ashok Kumar Roy, resident of West Bengal, the officials said.
The other two are locals of Alamganj in Dhubri and identified as Amir Hamza and Ismail Hussain.
