“She had a hard life and a hard journey,” he said, sitting in his lounge room next to the wall that separated them, his two dogs were at his feet and photos of his teenage daughter, who lives with him, framed on the wall behind.

"She would be doing OK and all of a sudden it got too much for her. You could hear her from everywhere, screaming at the kids, screaming at the neighbours," Philip said.

"She could be toxic."

The last time he saw Sarah was in December 2016, and she had found God, had broken up with her abusive boyfriend, and was off to church in a sundress with a smile.

Sarah, 40, had a long battle with addiction – one that she lost, and won, and lost again – and on that summer day she was winning.

“She was a very happy girl,” Philip said.

That’s how he likes to remember her.

Sarah's body was found in her bathtub in January. She had been killed in a violent assault in the Lambeth Street home between April 20 and 24 last year. Her corpse had lain there for eight months.

Sarah was known for disappearing, Philip said, so he hadn't considered it unusual that he hadn't seen her.

There was movement outside her house one day in June last year, and Philip caught her boyfriend going through her stack of mail in the letterbox.

Philip asked where Sarah was, to which he replied she’d been locked-up in a psychiatric hospital.

He tried to avoid Philip after that when he saw him from time to time, before, in December 2017, he heard a number of people coming and going. His front windows shuddered every time the door next to him would slam.

Police went to Sarah's home on January 3 to issue a witness summons to attend court in Moe. Instead they found her badly decomposed body. Philip had been away those days in April and he had never since noticed a smell coming from behind the wall.

Homicide squad boss Tim Day revealed on Tuesday that there were people who had been creating a ruse that the mother of four was still alive.

Detective Inspector Day said three men and two women were questioned when Sarah's body was discovered, but no one has been charged. They all remain persons of interest. Inspector Day urged anyone that had spoken to people who had acted as if Sarah was alive after the April dates to come forward.

It could be second or third-hand information, he said, but it could lead back to those peddling the lie that she was still alive.

“This could be from a range of people including neighbours, friends, passersby or any local businesses she had contact with,” Inspector Day said.

Sarah had stopped speaking with her father, Victor Gatt, and stepmother, Cheryl Gatt, about 18 months before her body was found. Victor said they too had tried time and time again to help Sarah get clean after she started using in her late teens.

“I lost my daughter,” Victor said.

“I should have pushed myself to go and see her, but Sarah is the type of person if she doesn’t want to see you, she doesn’t want to see you."

Sarah had aspired to be a model in her late teens, and had got photographs taken for her portfolio, which the family shared on Tuesday.

Both Victor and Philip had said something happened to her back then. Philip believes she had been preyed upon by someone in the modelling industry.

On Tuesday, there were sounds coming through the walls from Sarah’s home into Philip’s lounge room. Tradies were tearing apart the inside, putting it back together so it looked fresh for Philip's new neighbours to move in next week.

"People had been coming and going from that house. They knew," Philip said.

"Sarah was a human being with her own foibles, but she deserved a hell of a lot more than what she got."

Anyone with information is urged to phone Crime Stoppers on 1800 333 000 or submit an anonymous report online.