A community is in mourning after a seven-month-old baby boy died in a suspected drowning at a popular campsite near Gympie, north of the Sunshine Coast.

Emergency services were called to the Chatsworth Park rest area about 10.30am on Saturday, after the boy’s mother found him in a nearby lake, roughly 50 metres from their campsite.

Bystanders desperately performed CPR while waiting for paramedics, who rushed the critically injured child to Gympie Hospital. Despite efforts to save him, the baby died later that night.

The family had stopped at the free campground for the night while returning to their home in North Queensland.

Detective Inspector Craig Mansfield said on Monday that the death was being treated as “unexplained”, and that investigations were ongoing.

However, on Tuesday, a 42-year-old man – who police say is known to the child – was arrested in Bundamba, west of Brisbane. He has since been charged with manslaughter (domestic violence).

The man is due to appear in Ipswich Magistrates Court.

The heartbreaking case has shaken locals and left many seeking answers about how such a tragedy could unfold during what was meant to be a peaceful family stopover.

Images: WIN TV / 7 NEWS