A Sydney man was found guilty of abusing and murdering his girlfriend's two-year-old daughter and has been jailed for at least 33 years.

A jury at the New South Wales Supreme Court deliberated for just eight hours and rejected 25-year-old Mohammed Khazma's claim that it was the girlfriend who was responsible for the toddler's death before delivering a guilty verdict on one count of murder and two counts of assault.

Justice Elizabeth Fullerton subsequently sentenced him to 44 years behind bars, with the non-parole period set at 33 years. The sentence was backdated to December 2016, when the toddler was murdered, meaning the earliest Khazma can walk out of prison is December 2049.

According to the Daily Mail, the guilty verdict came after the abuse Khazma doled out on the young girl at his and his girlfriend's apartment in Sydney was detailed to the jury. They were told that the 25-year-old burned the toddler repeatedly with a cigarette lighter, including on the genitals, and slammed her head into a wall in the lead-up to her death.

Footage captured by a CCTV camera on December 19, 2016, the day of the toddler's death, showed Khazma and his girlfriend, whose identity has not been revealed, fleeing their apartment with her hidden under a blanket.

After she died, a forensic pathologist found that the girl had suffered more than 100 wounds, including 28 human bite marks on her arms, legs, and buttocks, as well as cigarette burns, cuts, and bruises. She was also found to have "massive bleeding" in her skull consistent with a traumatic injury. The authorities arrested and charged both with murder.

During his defense, Khazma countered by claiming he had "never laid a finger" on the toddler and that it was his girlfriend who pinched, punched, hit, and whipped her. He said he wanted to report the abuse but didn't do so because he didn't want her to get into trouble.

However, the mother later pleaded guilty to manslaughter on the basis that she failed to remove her daughter from Khazma's abuse. She had given evidence that disciplining from her side just involved sending her two children to "the corner for five minutes" and that it was her boyfriend who got violent.

She also claimed that he had bashed the two-year-old's head against the wall while her back was turned and that it caused the toddler to turn "a brownish purple color" and vomit a black liquid. She has already served her prison sentence and is now free.

The jury later ruled that it was Khazma who was responsible for the death and the judge expressed that she was satisfied the 25-year-old was responsible for most of the child's 114 injuries. Justice Fullerton said he derived "some perverse pleasure from the pain the child will inevitably have suffered."

She said a life sentence was not warranted but that his offenses were "very grave." Speaking during his sentencing, the judge said, "The girl was] not simply vulnerable and defenseless because of her age ... but she was without any agency of her own or capacity to defend herself from the two adults who were, in different ways, ultimately criminally responsible for her death."