Three years after Peta Fairhead was dumped at hospital and died, her case is going back to court

Peta Fairhead was found badly hurt outside Joondalup Health Campus, where she later died.

Three men found guilty of killing a woman who was dumped outside a Perth hospital have had their convictions quashed and a retrial ordered.

Mother-of-three Peta Fairhead, 27, died a short time after being left at the front door of the Joondalup Health Campus in the city's north in August 2016.

Lucas James Yarran, Ross James Boag and Leroy Daniel Smith were last year found guilty of her unlawful killing, after it was alleged she had suffered a fatal injury when she either jumped or fell out of a car to escape from them.

At their Supreme Court trial it was alleged the men had earlier detained and robbed Ms Fairhead after she had driven two male acquaintances to Mr Yarran's home in the Perth suburb of Ridgewood.

Mr Yarran was sentenced to 11 years in prison, while Mr Boag and Mr Smith were each given terms of 10-and-a-half years.

Today the Court of Appeal unanimously overturned the men's convictions and ordered that they face a retrial.

The reasons for the court's decision were suppressed.

The three men, who were all aged in their 20s at the time of their convictions, were not present for the judgment.

They were remanded to appear in court next week, when a date may be set for the retrial.