A 16-year-old Bronx charter school student was allegedly beaten and robbed by his science teacher after he kept $4K the teacher gave him to buy marijuana.

Kevin Pope, 48, who teaches at the John V. Lindsay Wildcat Academy in Hunts Point, was arrested yesterday for allegedly attacking the unidentified teen on Wednesday. Pope had apparently asked students to find him a dealer to sell him a pound of pot, and the teen told him he'd make the deal for him. The teen told cops he spent the money instead, after finding out the pound would have cost $7K; he says when Pope found out three months later, he accosted him a few blocks from the school and hit him in the face several times.

Pope also allegedly "threatened to have him beat up again and have his mother sexually ­assaulted," according to the Post, and told him, "I will kill you if I don’t get my money!" The teen says Pope took his gold chain, iPhone and wallet as compensation for the lost cash.

Pope was charged with assault and robbery.