The North Queensland family was passing through the Gympie area on their way home and stopped at Chatsworth Park on Gympie Curra Road to stay on Friday night.

The baby was found at the lake at 10.30am on Saturday and the boy’s mother raised the alarm with emergency services.

This was followed by multiple calls made to triple zero.

Detective Inspector Craig Mansfield said the child was rushed to Gympie Hospital but died on Saturday night.

“They were just staying there overnight and, tragically, this incident has happened the following morning,” Mansfield said.

“The mother of the child did retrieve the child from the water.

“It’s been a very traumatic experience for her, clearly.”

Mansfield said police would like to speak to anyone who was in the area or at the rest stop between 9am and 11am on Saturday as they investigate how the seven-month-old came to be in the water.

“We’ve had a lot of campers staying there overnight,” Mansfield said.

“We’ve also had a lot of people just popping in to use the facilities and the parks.

“We’re aware that some people have left shortly or thereabouts at the time of the drowning of this infant child.

“We’re treating this as an unexplained death at this point in time.

“We know what’s happened, we’re just investigating further to try and establish why and how this incident occurred.”

Mansfield said the child trauma unit and the homicide investigation squad would provide some support to local detectives to bolster resources.

“It’s a resourcing issue here for us, so the more people we can have involved, the better,” he said.