New South Wales Deputy State Coroner Paul MacMahon said he was not satisfied the 33-year-old committed suicide, instead declaring an open finding.
That decision was prompted by her family's private investigation, after she was found dead in the shower of her Sydney apartment on December 3, 2009.
Police later concluded Miss Haag had taken her own life, after a suicide note, pills and a razor were found at the scene. Unconvinced, her family carried out their own investigation.
Their evidence included the discovery of a note saying ''he did it'', a marking of a tile saying ''he did it'', evidence of a struggle, a lack of blood at the scene, knives missing, a toxicology report, and Miss Haag's positive outlook on life.
Evidence from her diary and from the Haag family showed her former partner Nastore Guizzon was a bully who behaved in an intimidatory, controlling and abusive manner towards her.
''Guizzon denied this evidence; however, other witnesses corroborated the assertion,'' Mr MacMahon noted.
He also noted the movements of Mr Guizzon, the father of their young child, on the day of her death, ''and his subsequent evidence concerning those movements also gave rise to real suspicion as to the possibility of his involvement in Nadine's death''.
Mr Guizzon has denied any involvement in Miss Haag's death.
In his findings, the coroner said ''Nadine's circumstances at the time of her death are most unusual for a suicide''.
''In my years as a coroner I have had to investigate many deaths that were due to suicide. In the vast majority of such cases the investigation of the death will identify one or more aspects of the deceased's life that provides an explanation, or at least a clue, as to why they acted to end their life.
''The investigation of Nadine's death did not show this to be the case.''
Last week the family issued a statement to the Otago Daily Times saying they were hoping for a finding that would warrant further investigations.
Yesterday their lawyer called on police to conduct an investigation into the matter.
