Investigators have told the suspected murderer of Sydney Aboriginal woman Cheryl Ardler "we're coming for you" as her heartbroken family welcome a $750,000 reward.
The 41-year-old was last seen by neighbours near her Cranebrook home in the days leading up to Christmas in 2012, and human remains located in nearby bushland in May this year confirmed the bones belong to Ms Ardler.
NSW Police announced the reward on Thursday alongside Ms Ardler's family at a news conference in Sydney.
Her sister Josephine, wiping away tears and embraced by her surviving sisters, described Cheryl as a proud Aboriginal woman who loved life, her son and family.
"Our family is so devastated to know we will never see or speak to Cheryl again," she said.
"Our hearts are broken, this has changed our lives forever."
She pleaded with the community, particularly Aboriginal people, to come to police with information that could solve the case.
Homicide squad commander Scott Cook said investigators believed one person, potentially known to Cheryl, was behind her killing.
"Hand yourself in, we're coming for you, we're coming for you, hand yourself in," he said.
Det Supt Cook said he believed people in the area knew more than they had told police and he hoped the new $750,000 reward would give them an incentive.
"You owe it to Cheryl to come forward beyond any amount of money," he said.
Investigators located "items" significant to the investigation with Cheryl's remains, Det Supt Cook said, noting the person who killed her will likely know what they are.