A script supervisor who worked on the film 'Rust' is suing Alec Baldwin, claiming he recklessly fired a gun and was "play[ing] Russian roulette" in his handling of the weapon.

Alec Baldwin was both one of the stars of and a producer on 'Rust', which was being filmed in New Mexico.

Baldwin fired a prop gun while on set, which killed cinematographer Halyna Hutchins and injured director Joel Souza.

Script supervisor Mamie Mitchell has filed a lawsuit claiming that he fired the weapon when "there was nothing in the script about the gun being discharged by defendant Baldwin or by any other person."

The scene required three close-up shots, according to the lawsuit: one on his eyes, one on a blood stain on his shoulder, and one on his torso as he pulled the gun from a holster.

This is now the second lawsuit to emerge following the shooting. Head of lighting Serge Svetnoy has also filed a suit in the Los Angeles Superior Court.

Mitchell's attorney Gloria Allred says at a press conference that: "Mr. Baldwin chose to play Russian roulette when he fired a gun without checking it, and without having the armorer do so in his presence.

"His behaviour and that of the producers on Rust was reckless."

The weapon was given to Alec Baldwin by assistant director Dave Halls, who is said to have shouted "cold gun", meaning that the weapon was unloaded with live rounds, before passing it to the actor.

According to the lawsuit, Mitchell was the first to call 911 after the shooting.

She was allegedly less than four feet from Halyna Hutchins when she was shot and described hearing a "deafening loud gunshot."

She said she heard someone moaning, saw the "director was falling backward and holding his upper body", and then witnessed Hutchins sink to the ground.

She ran out of the wooden church set and used her iPhone to call emergency services.

Her lawsuit reads: "Alec Baldwin intentionally, without just cause or excuse, cocked and fired the loaded gun even though the upcoming scene to be filmed did not call for the cocking and firing of a firearm."

Mitchell is is seeking both compensation and punitive damages in amounts to be determined later.