The police said Kausar Ali, a member of CPI-M zonal committee in Raina, and his aide Allaudin Kazi were arrested from their houses at Polempur in Raina police station on the outskirts of Burdwan town early today.
A 9 mm pistol, 9 mm carbine, 3 magazines and 37 cartridges were seized from their possession, the police said.
The police said they were associated with gun trading and used to supply arms and ammunition to those who would terrorise villagers.
CPI-M district secretary Amal Halder told mediapersons in a press conference that the police had implicated Kausar and his friend in a false case.
"It is a politically motivated move. The police themselves kept the arms and ammunition in his house to implicate him in a fictitious case," he said.
A local court later remanded the duo to seven days police custody.