A 45-year-old man has been jailed for life over the murder and torture of a Western Downs toddler more than seven years ago.

Aboriginal and Torres Strait Islander readers are advised this article includes the name and image of a person who has died.

Tane Saul Desatge was on Tuesday convicted of the murder and torture of his stepdaughter, two-year-old Kaydence Mills, in Chinchilla in 2017.

Today, a Supreme Court judge told Desatge it was difficult to comprehend his horrific actions toward the little girl and that his appalling conduct must be denounced in the strongest terms.

Justice Sean Cooper said Desatge used considerable force to inflict injuries upon Kaydence and also decided not to seek medical treatment for the little girl.

"You had a significant degree of animosity towards Mr Mills [Kaydence's birth father], and it influenced your feelings and treatment of Kaydence."

Justice Cooper said Desatge's appalling conduct must be denounced in the strongest terms and jailed him for at least 22 years.

"The death of your moral culpability and horrific nature of your actions … in killing Kaydence, means the element of denunciation will not be served by a minimum non-parole period of 20 years," Justice Cooper told the court.

Kaydence's remains were found near the Chinchilla Weir in March 2020 after an investigation was launched into her whereabouts the previous year.

Desatge had pleaded not guilty to murder and torture, but guilty to two counts of interfering with a corpse during a judge-only trial in Toowoomba in July and August.

But Justice Cooper found the 45-year-old had beaten Kaydence in the head and face with a bamboo stick at their Chinchilla home in 2017, causing her death.

'Complete and utter lack of remorse'

He found it was Desatge's animosity towards Kaydence's birth father, Robert Mills, that motivated him to hit the little girl.

In his submissions to the court, crown prosecutor Michael Lehane asked for a jail sentence with a non-parole period of between 22 to 25 years, beyond the usual 20-year-long minimum sentence.

He said Desatge was a cruel, unrepentant, cold-hearted murderer.

"Kaydence was a completely vulnerable child subject to his cruel, inhumane treatment," Mr Lehane said.

"To say his acts were cowardly is an extreme understatement … his extreme bitterness towards Kaydence continued even after her death.

During the 12-day trial, prosecutors told the court the two-year-old was "destined to die" due to her mistreatment.

The court heard Kaydence was forced to sleep on the toilet floor, was often unclothed and was forced to eat her own faeces.

Mr Lehane said it took a sophisticated undercover police operation to draw out a partial confession from Desatge but even then, he sought to blame his co-accused and Kaydence's mother, Sinitta Tammy Dawita.

Desatge's lawyer Frank Martin KC said his client had offered to plead guilty to manslaughter and torture and had showed officers where Kaydence's body was.

"Twenty years is the mandatory sentence, there's nothing that makes [the case an] exception to take it out of those 20 years," Mr Martin said.

Desatge will be eligible for parole on March 1, 2042, taking into account more than 1,600 days in pre-sentence custody.

Mother acquitted of murder

Kaydence's mother, Sinitta Tammy Dawita, 32, was on Tuesday acquitted of the murder and torture charges.

She was sentenced to 18 months' jail after pleading guilty to two counts of interfering with a corpse.

Dawita had been due to be released on parole on Tuesday, but that was delayed for almost a week to allow her time to find somewhere to live.