Sylvester Stallone. (AP Files)

Sylvester Stallone has been slammed for flouting driving regulations by squeezing two children into the passenger seat of his car.

The action man was snapped in his Mustang on Sunday with two young girls sharing the front seat - a flagrant violation of California state law.

LAPD Detective Bill Bustos tells RadarOnline.com, "California law states you must have only one passenger per seat. Driving with two passengers in one seat is vehicle code violation 27360. You must have one passenger per seat belt."

And the Rocky star has also been blasted by the California Department of Motor Vehicles as the seat only has one seat belt: "Children ages six and older, but less than 16, and children under age six who weigh more than 60 pounds, must be properly secured in an appropriate child passenger restraint system or safety belt which meets federal safety standards.”

Stallone is not the only celebrity to be caught out violating motor laws recently - David Beckham was photographed using his cellphone while driving last month, and Arnold Schwarzenegger's wife Maria Shriver was also caught chatting on her handset.