Police officers should be stationed on all film productions where guns are being used, Alec Baldwin said Monday, weeks after he fatally shot a crew member in a tragic on-set accident in New Mexico.

The US actor and producer fired a Colt .45 he had been told was safe on the set of Western Rust, striking and killing cinematographer Halyna Hutchins.

"Every film/TV set that uses guns, fake or otherwise, should have a police officer on set, hired by the production, to specifically monitor weapons safety," Baldwin tweeted.

A police investigation into the tragic incident is in progress, with prosecutors refusing to rule out criminal charges against anyone, including Baldwin.

Ahead of a rehearsal involving a shooting scene, Baldwin had been handed a firearm and told it was a "cold gun" - industry speak for a prop that was deemed cleared and safe to use.

Baldwin has described the "incidental accident" as a "one in a trillion episode."

Calls have grown since the incident for better control of weapons on Hollywood sets, and Baldwin previously said the effort was "something I am extremely interested in."

An online petition to ban the presence of guns on sets has earned 110,000 signatures, with celebrities including Dwayne "The Rock" Johnson pledging to never again use real firearms in his films.

The sheriff investigating the shooting said there appeared to be "complacency" on set with regards to firearms, while the inexperience of the film's 24-year-old armorer has been criticized.

Hannah Gutierrez-Reed, the armorer, has said she had "no idea" where the live round came from.