A QUEENSLAND coroner has determined it was highly unlikely Ipswich mother Dulcie Isabelle Birt had died as a result of injures sustained in a car crash as the man who was jailed for her death repeatedly claimed.
Instead, he found the man who was jailed over her death more than likely caused it.
Ms Birt, 31, was last seen alive on October, 21, 2009, at her home she shared with her sons, a boarder and her new lover in Old Ipswich Rd at Riverview.
Her former lover Alwyn John Gwilliams, 44, was initially charged with murder and interfering with a corpse, but on the first day of his Brisbane Supreme Court last year he pleaded guilty to the lesser charge of manslaughter.
Gwilliams admitted he unlawfully killed Ms Birt in a drunken car crash before panicking and disposing her lifeless body in Jacobs Well.
Despite an extensive search, which included draining several waterways in the area, her body has never been recovered and cause of death never determined.
Coroner John Lock determined Gwilliams had completely fabricated the story he told police in order to confuse the investigation and to impede the discovery of the body in case it assisted in revealing the truth.
"There may have been a minor motor vehicle crash and she may have been injured but those injuries did not kill her," he said.
"What is most likely is that she suffered some other form of assault by Gwilliams following on from an argument.
"The nature of the assault cannot be ascertained at this stage but it is likely this caused her death.
"The recovery of her body may assist in reaching a conclusion on this issue or it may not.
"The subsequent stories about the vehicle accident were concocted by Gwilliams and his family members and particularly his mother have assisted in its perpetuation."
Mr Lock determined Ms Birt's remains were most likely located somewhere in vast and inhospitable bushland at Riverview.
"Gwilliams was seen in that area on a number of occasions after October 22, 2009, at night or in the early morning," he said.
"He may have moved the body from where it was initially placed or made further efforts to hide the body."
During his sentencing the court was told of Gwilliams' criminal history which included a prior conviction in 2003 for the assault and torture of a former partner at a quarry in New South Wales.
He is currently serving a 10-year sentence at the Southern Queensland Correctional Centre near Gatton.