The budy, in an advanced state of decomposition, was discovered by two walkers in bushland on Knights Hill, near the Illawarra Escarpment on Thursday evening.

Post mortem results revealed the woman, aged between her late teens and early thirties, may have died more than five years ago.

Although police don't know the cause of death, Camden Crime Manager Detective Inspector Jon Alt said they had enough information from the post mortem results to launch a murder investigation.

"Due to the location where the body was found, the fact that the body was found at all and the post mortem results we are treating her death as a murder," he said.

"We are confident it is a murder so we have launched a murder investigation and have formed a strike force to investigate this death."

The post mortem revealed the woman had a cleft pallet which may have caused further disfigurement to the left side of her face.

Police said the woman was approximately 148 to 163 cm tall, had brown hair and was wearing a yellow singlet top when her body was found.

Police also found a set of earings nearby to the crime scene.

Further forensic testing has been ordered by police and is expected to take a number of weeks.

Detective Inspector Alt said police didn't have any early leads to the identity of the body, but were looking through local missing people files to try and work out the identity .

Police are appealing for information about anyone who may have gone missing in that area through the last few years.

Anyone with information is asked to contact Strike Force Abundance Detectives at Bowral Police Station on 48629 299 or Crimestoppers on 1800 333 000.