Four US police officers who rescued a baby from a submerged car after it had crashed into a river say they were guided by a woman’s voice asking for help.

The Utah officers rescued the 18-month-old baby girl, who was dangling from her car seat after a crash that killed her mother Lynn Groesbeck, 25, on impact 14 hours earlier.

They discovered the car and turned it over when they found baby Lily unconscious but alive.

• Baby found alive 14 hours after crash kills mother 

But since then, the police officers have been asking whose voice they heard.

A fisherman found the child and woman on Saturday. Photo: ABC

“For two nights I’ve laid awake trying to figure out exactly what it could be. All I know is it was there, we all heard it,” Officer Tyler Beddoes told Metro News.

“That’s the part that really sends me for a whirl. I’m not really religious, but that’s what you think of.”

The Examiner.com reports Spanish Fork Police Department officer Jared Warner found Lily hanging upside down from her car seat, saying the toddler was dangling in freezing water and she was still alive.

Officer Warner claims that he and three other police officers heard a woman’s voice yelling for help.

When the officers arrived at the wreckage, the driver was dead, and the baby couldn’t have screamed for help, he says.

“We’ve gotten together and just talk about it and all four of us can swear that we heard somebody inside the car saying help,” Officer Warner said.

Emergency services pull the wreck from the Spanish Fork River. Photo. Photo: AAP

A fisherman discovered the car on its top about 12:30pm on Saturday in the Spanish Fork River about 80km south of Salt Lake City, police Lieutenant Matt Johnson said.

The temperature dropped close to freezing overnight while Lily was trapped.

Investigators believe the wreck occurred about 10:30pm on Friday, when a resident near the scene reported hearing something.

The resident was unable to find anything out of the ordinary when checking the area.

The car struck a cement barrier on the bridge and careened into the river, investigators said. Police are unsure why the car left the road.

Relatives told police that Ms Groesbeck was heading home when the crash occurred.

– with AAP