NSW toddler burnt with cigarette lighter

A toddler suffered more than two dozen wounds including burns from a cigarette lighter to her face, limbs and genitals in the lead-up to her death, a Sydney jury has been told.

Forensic pathologist Lorraine du Toit-Prinsloo on Thursday testified there were about 28 human bite marks on the two-year-old's arms, legs and buttocks as well as burns in the shape of a cigarette lighter, inflicted before her death caused by "blunt force trauma".

But the doctor could not say what injuries caused the child's death or when they were inflicted.

Dr Toit-Prinsloo was giving evidence at the NSW Supreme Court trial of Mohammed Khazma, 25, who has pleaded not guilty to murdering his then-girlfriend's daughter in December 2016 in Sydney.

He has also denied accusations he assaulted the girl by deliberately burning her with a cigarette lighter and slamming her head into a wall in the days before she died.

A post-mortem examination revealed the toddler had suffered "massive bleeding" in her skull consistent with a traumatic injury, Dr Toit-Prinsloo said.

By the time the toddler was taken to hospital, the pathologist added, the girl was already near-death which "further complicated the dating of her injury".

"She was referred to hospital in a moribund state - she needed to be resuscitated and could not breathe on her own," Dr Toit-Prinsloo said.

The two-year-old had her life support switched off the next day.

Prosecutor Philip Hogan showed the jury a three-dimensional scan of the child's body, detailing injuries including 45 bruises, some of which were underneath yellow-tinged burn marks and scab-covered wounds.

Khazma's barrister, Luke Brasch, has previously told the jury the victim's mother caused her injuries and death but blamed her then-boyfriend to cover up her guilt.

The trial continues.