Isabella Huby was seated in a child’s booster car seat with an accessory H-style harness when she was killed in a car collision on Remembrance Drive on April 23, 2016.

Her father and driver Thomas Huby was charged with six offences relating to the crash, including culpable driving, dangerous driving causing death and driving while drug impaired.

Child car seat and booster seat expert Derek Wainohu told the Ballarat Magistrates' Court on Thursday the booster seat was not used in accordance to safety standards because the back had been removed.

He testified if the seat had been used as recommended by the manufacturer, it may have made a difference to the outcome of the crash.

But Mr Wainohu said he could not confirm that definitely.

Mr Wainohu said by removing the back of the seat, the InfaSecure booster seat was converted to a cushion.

“It’s a booster cushion that would not comply with standards,” Mr Wainohu said.

“The (model) was never designed to be used as a booster cushion but a booster seat.”

He said the InfaSecure child’s seat the four-year-old was sitting in remained on the market.

Mr Wainohu said a travel H-style harness could cause potential harm to a child in a car collision if it was not correctly adjusted.

Senior Constable Benjamin Hay, who was the first police officer at the crash scene, told the court Huby was highly distressed and emotional but was responding in a rational manner.

He said he could not inform an opinion if Huby was drug-affected. Huby was breath tested at the scene before an ambulance transported him to hospital.

An expert, who reconstructed the crash, told the court there was no evidence the driver braked before he collided with a tree.

She said the driver may have been asleep when he collided with the tree.

The court was told investigators estimated the driver was travelling at 81km/h when he collided with the tree.

Huby pleaded not guilty to the six charges on Thursday. Magistrate Gregory Robinson committed him to stand trial at the County Court.

A directions hearing will be held during the Ballarat circuit starting on September 14.