New Jersey police released bodycam footage showing the moments before an officer pummeled a young woman during an off-the-rails arrest at a Wildwood beach — an incident that went viral after cellphone footage of the beatdown circulated on social media.

The 9-minute clip shows cops administer a Breathalyzer to 20-year-old Emily Weinman and another girl as they question the underage women about booze found near their beach blankets.

Weinman appears to pass the test but then becomes hostile and refuses to give her last name when asked.

“You’re mad because you thought we were drinking,” she says, according to video.

“OK, that’s it — I’m done with you,” the officer eventually says, asking his partner if he has any handcuffs on him.

Then Weinman begins to back away, shouting, “Don’t touch me.”

“You’re about to get dropped,” the frustrated officer can be heard saying moments later.

As he gets closer, Weinman shoves the officer, her hands temporarily blocking the bodycam.

When a clear picture emerges again moments later, the officer appears to be wrestling her to the ground by her ponytail, footage shows.

“You’re choking me. I can’t breathe,” Weinman shouts.

The scuffle continues and then the cop can be heard saying “That’s it” as he rears back and begins punching her.

Video of the beatdown went viral last week.

The officers eventually get her into cuffs and a waiting police vehicle.

“She tried kicking at us so I slammed her on the ground. She kicked him, so I hit her a couple times and put her in cuffs,” the officer can be heard telling a group of cops after the scuffle.

Cops slapped Weinman with several charges — including two counts of aggravated assault on an officer and possession of alcohol as a minor.

The officers were put on administrative duty while officials investigate the incident.