The accused, identified as SI of Sankrail Police Station Sumanta Mukherjee, and constables Durjodhan Malik and Susanta Guchhait, were caught red-handed while they were collecting money from a truck driver at Dhulagarh crossing, they said.
Acting on a tip-off, an anti-corruption wing of police arrived at the spot near the truck terminal.
The anti-corruption personnel took the three, who were on patrol, to the nearby police station and interrogated.
They have been suspended and a departmental probe has been ordered.