An 18-year-old woman claims two Brooklyn detectives forced her to perform sex acts in an unmarked police van in exchange for letting her walk free, according to police sources and the alleged victim’s lawyer.

The Brooklyn teenager told cops one of the narcotics officers raped her and both forced her to give them oral sex in a Chipotle parking lot on Sept. 15, after threatening to take her to the police station.

The officers targeted the woman after finding prescription drugs in a car during a traffic stop in Calvert Vaux Park in Coney Island, according to her lawyer, Michael David.

The cops allegedly let two young men who were with her drive off, but forced the teen to remain with them. Claiming they were searching for drugs, they ordered her to undress, the lawyer said. They didn’t find any narcotics on her, he said, but they cuffed her anyway.

They then pressured her into sex, her lawyer said.

“You’ll spend three hours in the precinct,” they allegedly told her, according to the lawyer, who said they added: “This is what you’re going to do for us, and we’ll let you go.”

“There was zero consent,” David said. “The cops were over 6 feet tall. She’s very petite, like 5-2 and maybe 100 pounds. There’s nothing she could do.”

The detectives from the NYPD’s Brooklyn South narcotics squad claim the acts were consensual, police sources said.

The Brooklyn District Attorney’s Office is investigating the teenager’s claims, law enforcement sources said. The Internal Affairs Bureau is also investigating and has called in multiple police officers for questioning.

The head of the detectives union said he couldn’t comment on the allegations.

“It would be inappropriate for me to comment because there is an active investigation going on,” Detectives Endowment Association president Michael Palladino said.

Her lawyer, meanwhile, has filed a notice of claim, the precursor to a lawsuit, against the city.