SHOCKING footage has emerged of a McDonald’s worker brutally attacking a customer.

The clip, posted on Instagram by user bxbyness on Wednesday night, was filmed in Las Vegas.

It starts off with the customer hurling a milkshake over the counter towards the employee.

She then strikes the worker with a metal tray. BAD MOVE.

The McDonald’s staffer doesn’t hold back. She punches the female customer repeatedly and tosses her around like a rag doll.

At one point she holds her down against the countertop and in another move she throws her into a booth.

Another staffer tries to stop the fight but also gets hit. That employee then hits the customer as she struggles to keep her top on.

There is a moment of calm when the staff stop and walk away.

At one point the customer considers fighting back but is pushed away.

Marie Dayag, the customer that captured the footage, said the fight started over a free soda.

“So this happened at McDonald’s … the lady asked for a water cup and supervisor shut down the soda machine because she wasn’t letting her get a free soda,” Dayag said in a post on Facebook.

A spokesperson for McDonald’s said the company is investigating the incident.

“We do not condone the behaviour depicted in this video,” the spokesperson told TMZ.