Nadine Ana Haag (33) was found dead in her Castle Hill apartment, in northwest Sydney, on December 3, 2009.
A note, pills and a razor were found at the scene, leading police to conclude she had taken her own life.
However, her family disagreed with that decision and began their own investigation.
Following her death, her family came back to Dunedin and the suburb of Brockville in January 2010 to visit, and to allow friends to pay their respects to Nadine.
Last month, her sister Chantal wrote on the Dunedin suburb's Facebook page:
"At the time we were not able to say much about the circumstances surrounding Nadine's death as it was still being investigated by the NSW police".
"We hope that this may explain why we were quiet about her death."
The family's story featured last month on the Australian current affair show Sunday Night, which confirmed a New South Wales coroner had recommended an inquest into Nadine's death.
That inquest was expected to include evidence gathered by her brother, Marcel, and sisters Cherie, Chantal and Tasia.
The television show revealed how the four siblings re-created the crime scene, which included gathering and reviewing evidence, and talking to neighbours.
Nadine had been in an allegedly volatile relationship.
Her former partner has strenuously denied any involvement in her death, Sunday Night reported.
On the day of her death she had an appointment with a lawyer and had made plans to return with her young daughter to their family in Queensland.
Her body was found the following day in the shower.
As her death was treated as a suicide, police did no forensics work and took no fingerprints or DNA from the scene.
As part of their private investigations, the siblings found tucked behind the original suicide note; a message saying: "He did it".
The same words were found just a few months ago - etched on a low tile in the bathroom - by new residents of Nadine's former apartment.
Sunday Night also reported the siblings could not locate the brown dress their sister was wearing on the day she died.
Toxicology reports, based on the empty packets of pills located at the scene, have indicated she had taken less than a therapeutic dose.
While a razer was found, Nadine's wound was considered to be so deep that another weapon may have been used.
The siblings were unable to find two knives from of a set of six belonging to the property.
The lack of blood from her artery as a result of it being cut has also been questioned by the family.
Nadine was described by a fellow former Kaikorai Valley High School pupil as "lovely".
"She had an outgoing personality and was very sporty."
Her family had posted a photo collage of Nadine on the video-sharing website YouTube. It ends with the message "I love you more than words can say, never stop loving, never stop living, never stop!"
The Otago Daily Times approached NSW police for comment but has had no response.