Heidi Strbak was sentenced to nine years’ jail in 2017 after pleading guilty to the manslaughter of her four-year-old son Tyrell Cobb.

In March, Strbak won a High Court appeal and her sentence was set aside and she faces a re-sentencing hearing before Justice David Boddice in the Brisbane Supreme Court on Monday.

Tyrell died in May 2009 after Strbak and her then de facto Matthew Scown failed to seek timely medical treatment for the sick boy.

He had been vomiting bile for two days following a blow to his abdomen, which cut open his small intestine.

Strbak’s sentence hearing was told she and Scown had committed acts of physical aggression towards Tyrell.

An autopsy revealed 70 bruises and abrasions, including a cigarette lighter burn on his ankle.

Strbak denied burning and slapping Tyrell. She also denied inflicting the blow that led to his death.

Scown was also convicted of Tyrell’s manslaughter and received a four-year sentence after the court found while he also failed to seek medical help, he was not responsible for the injuries.

Strbak previously appealed her sentence in the Queensland Court of Appeal on the grounds she did not inflict the blunt force injuries to Tyrell.

She called for a three-year reduction to the sentence but this was dismissed by the court.

The appeal court found there was no error in Justice Peter Applegarth’s conclusion that Strbak was likely to have punched Tyrell in the stomach and then struck him again when he vomited before his eventual death.

Scown had testified that he had seen Strbak abuse the boy, particularly when she was unable to obtain marijuana.

But the High Court of Australia granted Strbak’s appeal against the sentence after it found Justice Applegarth incorrectly assessed key facts in the case.

It said that on a number of occasions he accepted unproven prosecution evidence or a conclusion that reflected poorly on Strbak when determining her sentence.

This occurred because Strbak failed to give sworn evidence contradicting the prosecution at her sentence hearing.

-AAP