A lawyer for the family of an unarmed black motorist killed by a New Jersey state trooper is blasting a “cover up” after authorities claimed the slain man tried to grab the trooper’s gun and flee in his squad car.

Maurice Gordon’s relatives deny the explosive claims contained in the one-page New Jersey Attorney General document the Daily News exclusively obtained Sunday — and are demanding the release of a police video of the killing.

“Maurice did not physically engage the officer. The officer physically engaged him three separate times,” said William Wagstaff, an attorney representing Gordon’s family, who has been permitted to watch only selected portions of the video.

Wagstaff says Gordon tried to get inside the squad car only to escape the trooper during what started as a routine traffic stop on the Garden State Parkway in South Jersey on May 23.

“Only after being physically engaged by the officer did Maurice try to flee by the only means available,” Wagstaff said.

The trooper scuffled with Gordon outside the car and then fired at least four shots, Wagstaff said.

“The officer appeared irrational as he repeatedly yelled to Maurice, ‘Get out of the car! Get out of the car!’ when they were both approximately 20 feet from any vehicle,” Wagstaff said.

New Jersey Attorney General Gurbir Grewal has refused to release the entire video or basic information about the killing of Gordon.

His office is expected to release the video and audio tape along with the name of the trooper involved later Monday, after the family has seen it.

The document from his office obtained by The News claims that Gordon “attempted to take hand gun; attempted to take troop car.” Sharon Lauchaire, a spokeswoman for Grewal, confirmed the authenticity of the document to The News Sunday night.

The so-called 3B document did not include the name of the New Jersey State Police trooper who pulled the trigger, information that is supposed to be included.

Wagstaff says the video that he was shown also depicts two troopers “manhandling” Gordon’s bloody body after shooting him.

Troopers “(handcuffed) him as he lay dying on the side of the road after roughly manhandling his bullet-ridden body,” the lawyer said.

Authorities have not disclosed how long it took troopers to get medical attention and whether Gordon died at the scene of the shooting in Bass River, New Jersey, or elsewhere.

Gordon’s grieving mother, Racquel Barrett, has said she believes her son was murdered by racist cops and compared his death to the killing of George Floyd by police in Minneapolis that started a massive nationwide movement.

Gordon was driving for Uber and studying chemistry at Dutchess Community College in Poughkeepsie, where he lived.