A US toddler who was found unresponsive in an Arizona pool and declared dead was later discovered to be alive in the hospital's "cold room", a newly released police report shows.

The family of the 18-month-old frantically called police after they found him face down in the pool at a home in the Phoenix-area suburb of Gilbert on 8 February.

First responders were dispatched and performed life-saving measures, before the child was transported to hospital and declared dead an hour later.

According to the police report, officers told a physician at the hospital, Dr Aryan Toosi, that they had seen signs of life. The doctor responded, "please do your thing and let me do my thing", the report says.

"I went to medical school for a reason," Toosi said, according to the report.

Family had gathered to watch the NFL Super Bowl game when police were called to the scene for a reported drowning.

Gilbert police arrived to the home around 17:30 MST (00:30 GMT), before the child was taken to Mercy Gilbert Medical Center and pronounced dead at 18:20.

"If there's no objections, I'd like to call time of death," Toosi said, according to police officer bodycam video obtained by a local NBC News affiliate.

"Time of death 18:20. Moment of silence," the doctor said.

A transporter from the Maricopa County Medical Examiner's Office arrived to hospital five hours later and found the child was still breathing, according to police.

He was flown to another hospital where he recovered and has since been released.

Medical records for the child were not included in the police report, leaving uncertainty about what exactly happened.

The doctor's attorney, Scott Holden, told the BBC in an emailed statement: "Out of courtesy to the family and patient confidentiality, we respectfully decline to make a statement at this time."

Police are recommending negligence charges against the parents.

According to the police report, investigators said there was a strong smell of marijuana at the home, which led them to believe the child could have had unsupervised access to the pool.

The Maricopa County Attorney's Office has not yet said if it would seek to press charges.

Mercy Gilbert Medical Center said in a statement that the hospital conducted "a thorough review of all aspects of the care provided to learn what happened and to make meaningful changes to strengthen our care".

The hospital called it "a heartbreaking situation" and has declined to release any further details.