Hollywood actor Alec Baldwin fired a prop gun that killed a cinematographer and wounded the director while a film was being shot in New Mexico, according to reports in the US media.

The incident happened on the set of the upcoming film "Rust," based on a 19th-century western story in which Baldwin is playing the lead role.

A helicopter transported cinematographer Halyna Hutchins, 42, to the University of New Mexico Hospital, where she was pronounced dead by medical personnel, according to the Santa Fe County Sheriff’s Office. The director, 42-year-old Joel Souza, was transported via ambulance to Christus St. Vincent’s hospital and is receiving emergency treatment for his injuries, according to a report in USA Today.

"According to investigators it appears that the scene being filmed involved the use of a prop firearm when it was discharged. Detectives are investigating how and what type of projectile was discharged."

Another media report cited a source saying "a principal cast member" had cocked the gun during rehearsals, unaware that it contained live rounds.

Baldwin has starred in blockbusters such as "The Hunt for Red October" and "Mission: Impossible." He has also appeared on TV with his portrayal of Donald Trump on "Saturday Night Live", a character which won Baldwin a Primetime Emmy award.