Maureen, 57 at the time of her disappearance, was last seen by her daughter at the Seven Hills home the family shared on December 5, 2003.

The loving grandmother spent the morning of that fateful day playing with her one-year-old grandson, Bailey Nouredine, before setting out on her daily walk to visit friends.

But Maureen was never seen again.

“I can remember it like it was yesterday,” Maureen’s daughter, Natasha Nouredine told the Blacktown Advocate.

“It was no different to any other day.

“She said she was going to the local shops, she was going to take a walk, and that was it.”

Natasha said there were no warning signs or alarm bells that would have led the family to believe Maureen would leave them behind for a new life, revealing in the week prior she had informed her mother that she was pregnant.

“I’d just told my mum that we were expecting another child,” she said.

“This was a time where you should be happy and the stress of it all was horrible.”

But the 57-year-old’s sister Anne Lalor, said Maureen became distant in the weeks leading up to her disappearance, crediting changes to her association with new friends.

“I just think these people she met up with, they weren’t very nice people,” Anne said.

“She started changing.

“We used to go to the shops every week — then she sort of stopped coming.”

Anne said Maureen began using her new friends as an excuse as to why she could not spend time with the family.

Despite extensive investigations and an ongoing campaign for information by her family, the disappearance of Maureen, who would be 71 today, remains unsolved.

Natasha revealed her mother suffered from bipolar disorder, and was receiving treatment through ongoing medication.

“She was a great mum,” she said. “Especially in her early years before she got sick with her bipolar.

“At the time (of her disappearance) she was medicated and she was fine, but she definitely had times in her life when she had her ups and her downs.”

She believes it was that mental health diagnosis that led police to “brush off’ her mother’s case.

“Straight away they (police) assume that she’s run off or done something crazy,” Natasha said.

“They just sort of brushed it off at first and didn’t really take it seriously.”

The investigation into Ms Matterson’s disappearance was plagued by several contradictory statements around her last known whereabouts and a lengthy period of time where the family say they were forced to convince NSW Police their mother was a missing person.

Maureen’s new friends, who her daughter described as ‘undesirable’, provided little support for police.

A lack of sufficient evidence led investigators on a wild-goose chase across western Sydney. Conflicting accounts identified locations in Toongabbie, Lalor Park and Seven Hills as possible locations of where Maureen was last seen.

“I don’t think these people were of great character,” Natasha said.

“Those people she was associating with might know more than they let on.

“I truly believe that she didn’t run off, I think someone may have been responsible for her not coming back to us.”

The grandmother’s disappearance has left a trail of heartbreak in its wake.

Natasha and her brother Troy live on without their mother.

Her grandchildren rely on scarce photos to identify their grandmother, while her former husband Bruce, despite divorcing several years earlier, “died of broken heart”.

Natasha said she was forced to to terms with the death of her mother long ago — a coping mechanism she used for her “own sanity”.

However, other family members believe Maureen will one day be reunited with them — convinced she remains lost in Sydney.

HUNT CONTINUES FOR MAUREEN

POLICE identified Maureen as a missing person five days after she disappeared.

Despite Maureen’s family claiming police ‘bushed off her case’ due to her mental state, Detective Senior Sergeant Adam Wilson said investigators took the disappearance seriously from day one.

“From the time they took that initial report, police started searching almost immediately,” Det Wilson said. “(Searches) were based on the information they were told in relation to Maureen’s usual movements, places that she frequented, areas she went on a daily or weekly basis, friends she visited.”

A series of searches through dense bushland led to investigators discovering the only piece of evidence in the missing person’s case.

Maureen’s handbag, filled with her money, jewellery and other personal belongings, was found in a creek bed in Toongabbie.

“At the time she went missing she had about $500 that she had withdrawn from her account,” he said.

“Her handbag was later found in a creek and half of that money was still in it.”

Det Wilson said police were convinced there was no financial motive behind her disappearance, and revealed there were no persons of interest despite family’s concern around new friendships.

“It wasn’t good,” he said.

“She suffered from depression, she was on medication — she was also an alcoholic.”

Natasha, said the NSW Coroner’s court inquest, which was held in 2009, provided little information or support for the family.

Det Wilson said the case had been ‘finalised’ by the coroner, however, new information could lead to further investigations.

“The coroner handed down an open finding and Maureen’s body has never been located,” he said.

“ My opinion is only based on reviewing the case itself, it’s more likely than not that Maureen did take her own life.

“As very sad as that is to contemplate, that appears to be the case.”

EXPERIENCE LOST IN SYDNEY

READ NOW - EPISODE I: The Lime Green Van

A YOUNG man climbs into his lime green Bedford van in the dead of night to drive his girlfriend home - no one has seen them since.

READ NOW - EPISODE II: The Disappearance at Dawn

TIEMUZHEN Chalaer was a lover of music — this may have been what sparked his enthusiasm for an unregistered party deep in the bush — little did he know, it would cost him his life.

READ NOW - EPISODE III: The Boy on Boxing Day

IT IS Boxing Day, 1982, a young indigenous boy jumps the back fence of his Dundas Valley home to scurry off to Eastwood station — he is on a mission to borrow money for his mother — minutes later his brother goes after him, but Bradford Pholi is never seen again.

Lost in Sydney: The Series

Episode IV — The Bag in the Bush

Produced and presented by Jake McCallum and Heath Parkes-Hupton

jake.mccallum@news.com.au - heath.parkeshupton@news.com.au

Artwork by Daniel Murphy

Editing by Jake McCallum