Kunwarpal (40), the brother of former minister Ranveer Singh, owned a diary and had loaned Rs 25 lakhs to his neighbour Sonu, police said.
Sonu was holding up the money and their relationship soured over the matter.
Last night, Sonu and his three accomplices visited Kunwarpal's house and took him away on the pretext of settling the debt.
The accused took Kunwarpal in a car to a secluded spot near the canal and killed him, police said.
Divers today recovered the bullet-ridden body this evening from Lower Ganga Canal near Sanauta village, SP (City) Rajesh Kumar said, adding that a manhunt has been launched to nab the accused.