Acting on a tip off, the police held Munna Yadav for impersonating as police inspector near Gopalpur chowk and extorting money from truck drivers, Town police station in-charge Umashankar said.
Yadav's associate Omprakash, a policeman posted in Patna district, managed to give the cops a slip, he said.
The duo had snatched Rs 2000 from a truck driver after initially demanding Rs 25,000 from him for letting him go with the vehicle, Umashankar said.
Yadav, a native of Bimbsar village in Siwan district, has been booked under relevant provisions of the law, the police officer said.