Gun was declared safe before Alec Baldwin fired it

Actor Alec Baldwin was told a gun being used as a prop was safe before he fired it on the set of “Rust,” killing the film’s cinematographer.

That's according to a county sheriff's affidavit filed in Santa Fe magistrates court.

It says Baldwin was handed the firearm by the film's assistant director and told it was a "cold gun" which indicated it did not contain any live rounds.

Minutes later, the weapon fired when Baldwin pulled the trigger, killing cinematographer Halyna Hutchins and injuring the film's director, Joel Souza.

The affidavit said the assistant director did not know the prop gun contained live rounds.

On Friday, Baldwin said his heart was broken, tweeting:

"There are no words to convey my shock and sadness regarding the tragic accident that took the life of Halyna Hutchins, a wife, mother and deeply admired colleague of ours. I'm fully cooperating with the police investigation to address how this tragedy occurred.”

He added: "I am in touch with her husband, offering my support to him and his family.”

Baldwin was the co-producer of the film being made at Bonanza Creek Ranch.

Reports have emerged of complaints over unsafe conditions on set.

The Los Angeles Times and Deadline Hollywood reported that six or seven camera operators had walked out -just hours before the tragedy happened.

The news outlets reported there had been at least one previous misfire with the prop gun.

Reuters could not immediately confirm the accounts.

Rust Movie Productions did not respond to a request for comment on Friday but said in a statement that the safety of the cast and crew is its top priority.

The sheriff's department said on Friday no charges had been filed and the investigation remained open.