Relatives and family friends of a toddler hit and killed by a government agency car reversing out of a driveway in Ipswich, west of Brisbane, have paid tribute to him on social media.

An officer from the Department of Child Safety had just completed a routine visit when 15-month-old Braxton James Nowlan was struck by the officer's car at his grandmother's Ripley home about 1:20pm (AEST) on Monday.

He suffered serious head injuries and died at the scene a short time later.

On Tuesday, heartbroken relatives and family friends took to Facebook to pay tribute to Braxton.

"RIP little BRAXTON you will be sadly missed, our thoughts are with you and family," one wrote.

"Such a shock and very sad, but he is in God's care now. All our love, will be thinking of you all," another said.

Another remembered him as a "beautiful angel".

A Department of Communities, Child Safety and Disability Services spokesman confirmed one of its cars was involved in the incident.

"The department is providing the utmost care and support to both family members and staff," the spokesman said.

"The department will review this incident and this review will also be externally scrutinised."

The police are continuing their investigation and will also prepare a report for the coroner's office.