UPDATE: Baby On Beach Being Treated As Homicide

A nine-month-old baby girl has been found dead on a Gold Coast beach and her parents now at the centre of a homicide investigation.

Queensland police say the baby had been in the water at some point before she was found alone and lifeless on Surfers Paradise Beach in the early hours of Monday morning.

She had no obvious injuries and hadn't been reported missing.

Police later located the baby's father, 48, and mother, 23, at Broadbeach, about five kilometres away from the crime scene.

They are known to police and will be questioned later in the day.

A passer-by found the child's body at the edge of the surf and raised the alarm but police say paramedics never stood any chance of reviving her.

Gold Coast Criminal Investigation Branch Detective Inspector Marc Hogan described the beach where the girl was found as "not your typical crime scene".

He said a ground and air search had yielded little evidence, with the lack of physical evidence giving "some indication of what may have happened" - a suggestion the child may have drowned.

"This is a very tragic event. It's a very sad situation," Insp Hogan has told reporters.

"It will impact a lot of people."

Homicide detectives from Queensland and NSW police are involved in the investigation.

NSW officers have been brought in to pin down potential movements of the couple between Tweed Heads, on the Queensland/NSW border, and Surfers Paradise.

Insp Hogan said they had been staying on the Gold Coast but did not say for how long.

The baby was found near the intersection of Staghorn Avenue and The Esplanade, less than a kilometre from the main party precinct for schoolies revellers.

But police don't believe the incident is related to the end of high school celebrations, and it wasn't a schoolie who found the child.

Detectives are checking CCTV footage, in the hope the couple and child may have been caught on camera.

A post-mortem examination will be conducted on Monday.