According to the Vanrai police, Rishab Jain (23), who helps his father in his cloth business, got a call two weeks ago from an unknown person who said he needed Rs five lakh for contesting the forthcoming elections.
Jain disconnected without replying.
On Thursday evening last, a man shot him in his office from a country-made revolver and the bullet grazed Jain's finger, they said.
Jain's workers caught the assailant, who was later identified as Ravi Shankar Prasad (32).
"We have arrested Prasad but we suspect insider's role," said an officer, adding that a revolver was recovered from Prasad.
He has been booked for extortion and attempt to murder under the Indian Penal Code and the relevant sections of the Arms Act.