The actor shot a camerawoman while filming the western film "Rust" with Alec Baldwin.
"According to the investigators, it appears that while filming a scene a prop weapon was used that was fired," said the sheriff of Santa Fe, New Mexico on Thursday.
He later stated that it was Baldwin who fired the gun.
The dead person is reportedly camerawoman Halyna Hutchins.
The director Joel Souza was also injured in the incident.
The entertainment magazine Deadline had already reported that "a leading actor" in the film cocked the gun during rehearsals without knowing that it contained live ammunition.
A spokesman for the production company confirmed that there had been an "accident" "in which a blank gun revolver was accidentally fired".
Cinematographer died in the hospital
The 42-year-old Hutchins was flown to the hospital, according to the sheriff, but succumbed to her injuries.
The also 42-year-old Souza was taken to another hospital in an ambulance, where he received emergency care.
Baldwin is involved in the filming as co-producer and lead actor.
In the western, he plays Harland Rust, an outlaw who flees the law with his grandson who has been sentenced to death for murder.
The 63-year-old is known, among other things, for his leading role in the literary film adaptation “Hunt for Red October” from 1990 and appearances in the film series “Mission: Impossible”.
During Donald Trump's tenure, he regularly imitated the now ex-US President on the program "Saturday Night Live".