Toddler's death: What happened to Connor?

The grieving family of a Queensland toddler who died in the care of a babysitter is begging for answers almost a year and a half after his death.

Connor Horan was two-years-old when a woman who was babysitting him took him to hospital at Warwick, on the Southern Downs, where he was declared dead from multiple head and internal injuries.

Police were told the little boy had fallen down a small set of stairs.

But child trauma detectives are conducting a full investigation, promising to find out exactly what happened before Connor was taken to the Warwick Base Hospital at 11.30am on Sunday, August 19, 2018.

"We are committed to providing the child's family with the answers they deserve following such a tragic event," Detective Acting Inspector Matt Howard said on Tuesday.

"Detectives are piecing together a timeline of events from that weekend and are seeking the assistance of the public to help us fully understand the circumstances of what happened."

Detectives want to hear from anyone who was in the Warwick area at the time and saw Connor, or has any information about what happened on that weekend.

The little boy had been staying with the babysitter, 38, at her East Street residence since the Friday before he died.

Post-mortem results are among the evidence being considered by officers from the Child Trauma Unit and the Darling Downs District Crime Group.

A video statement from Connor's mother, Emily Horan, and grandmother, Deborah Ballard, will be released later on Tuesday.

Ms Ballard says the little boy is never out of their minds.

"My family needs to know why my grandson died that day. It's destroyed our family not knowing what's happened.

"If anyone knows any information or has seen my grandson or the babysitter over that weekend, please go to the police."