NSW musician's body found naked at dam

How a woman's naked, decomposing body ended up on the remote foreshore of a dam in NSW's Blue Mountains has her family and police mystified.

Cecilia Devine's brothers on Wednesday appealed for help in tracing the Newcastle musician's last moments, after forensic tests confirmed the remains found at Upper Cascade Creek dam in March were hers.

The 42-year-old hadn't been seen since September 6, when CCTV footage captured her buying some food, a scarf, a jumper and shoes from shops in Katoomba.

But nothing was found with her body or nearby.

"It had been there a fair while," Detective Inspector Scott McAlpine told reporters in Sydney on Wednesday.

"It's a closed-off area, it's not open to the public because it's a catchment area for the Sydney water authority. Tourists wouldn't probably go there as a matter of course."

Police have searched the dense bushland and dam several times without success and still have not determined a cause of death.

At this stage, they are treating the death as suspicious and are being assisted by the homicide squad.

"We're open to all avenues of investigation," Det Insp McAlpine said.

Ms Devine, who was also known as Kristen Pearson, loved making music and was "probably way too easy going", her brother said.

"She just loved being part of the social life, that's where she was devoted with her singing," Nathan Pearson told reporters.

"She'd assimilate with anyone."

Another brother, Troy Pearson, revealed Ms Devine suffered from bipolar disorder, a chronic mental health condition.

"That plays a big part in her issue," he said.

Ms Devine was reported missing on September 5, 2018, from Waratah, a suburb in Newcastle, after family and friends were unable to find or contact her.

Police said at the time they had concerns for her welfare.