Prosecutors in the southern city of Namur said they had launched a manslaughter investigation following the incident, which took place on Thursday.

A forensics examination ruled out foul play and concluded the baby died of hyperthermia, or overheating.

"According to the preliminary findings of the investigation, the child was forgotten inside a vehicle," the prosecutor's office said.

Local media alleged that the father forgot to drop the baby off at daycare on his way to work.

The child was left for several hours inside the car at the man's company car park.

Temperatures in Namur reached around 25 degrees Celsius (77 degrees Fahrenheit) on Thursday afternoon.