The three have been identified as Nazrul Islam (55), Jainul Abedin (33) and Mohammad Kamrul Hoda (46), BSF Assistant Commandant Narendra Kumar Bola said.
While Islam hailed from North Dinajpur district of West Bengal, Abedin and Hoda belonged to Bihar's Purnea district.
The team seized 1.87 kg of snake venom powder which was kept in a glass jar. Two motorcycles and two mobile phones were also seized from them. he said.
Acting on a tip-off, a joint team of intelligence unit and the 146th battalion of BSF put up a mobile check post at Raskhowa Dhantola road near Qadirganj border outpost during which it intercepted two bikes coming from Raskhowa side and recovered the snake venom.
Later, the miscreants admitted during interrogation that it was snake venom powder kept in glass jar, he added.