The duo - Hakim Ali Sarkar (32) and Suleman Ali (38) - were picked up from a hotel at Gauripur town yesterday, they said.
The two were nabbed when they had come to the hotel for delivery of a consignment, BSF Frontier Headquarter Guwahati Deputy Commandant T K Chetri said.
Fake currency with the face value of Rs 50,000 in notes of hundred denomination were recovered from them.
"On questioning, the suspects divulged the name of a FICN kingpin Jafar Ali residing in Patamari area of Dhubri. Efforts are on to trace the suspect," Chetri said.
The duo also said that the fake currency was brought from Soalmari village in Bangladesh through the riverine border in Patamari under Dhubri district.