Remains of missing woman found 23 years on

The remains of a young woman who vanished in 2001 after checking out of hostel in the NSW Blue Mountains have been found.

Kellie Ann Carmichael was 24 years old when she travelled to Katoomba from her home in the Victorian city of Geelong.

She was last seen checking out of a hostel on April 29, in a cold case that has baffled investigators for 23 years.

Police discovered the woman's remains in bushland near Katoomba in April, during an unrelated police operation, and that more remains were found there in May, according to ABC and NewsCorp reports on Monday.

"The human remains initially located and seized have now been formally identified as those of missing person Kellie Ann Carmichael, and her family have now been notified," police said.

An investigation is being conducted by the Unsolved Homicide Team and a brief of evidence being prepared for the coroner.

Personal items Ms Carmichael took with her to the area have previously been found but human remains had not been located until now.

Police initially probed the possibility she took her own life, in part because she was suffering from schizophrenia, with the homicide squad first launching an investigation in 2004.

In 2011, a $200,000 reward was issued for information related to the case after a 2009 coronial inquest ruled Ms Carmichael had died but was unable to shed light on a cause or circumstances.

Ms Carmichael's parents Margaret and John have previously said they felt robbed by their daughter's mysterious disappearance.

"We've never had the chance to have our daughter ... our family has never been the same," Mrs Carmichael said in 2011.