Decomposed remains stuffed in a suitcase discovered in bushland in NSW yesterday are not human, police have revealed in a shock twist to the investigation.

Police were called to the grisly discovery in Oallen, about 60 kilometres south of Goulburn, at 12.50pm on Sunday.

A body has been found in a suitcase in bushland near Oallen, south of Goulburn, NSW. Nine

The body remains unidentified. Nine

Superintendent Linda Bradbury said the remains, which were significantly decomposed, had initially been mistaken for those of a human woman.

She said police did not, as a habit, significantly disturb human remains at a crime scene, meaning the remains had not been closely examined.

But testing this morning proved they were not human – though Bradbury said further testing would be needed to determine what their provenance was.

“So some good news here that we don’t have a suspicious death of a human on our hands,” she said.

She confirmed police would continue to investigate the incident, including identifying the source of the remains and how they came to be dumped in the bush.

Speaking to Today earlier this morning, Bradbury said a couple were out for a drive when they came across the discovery.

“They were out on a weekend drive as a lot of people do when they stopped for a break and found it,” she said.

“Quite a shocking discovery for them, absolutely.”

Bradbury said the remains were subject to a high degree of decomposition, leading police to suspect they had been there for some time.

After finding out the remains were not human, Bradbury said the couple who made the discovery did the right thing in calling police.

“Members of the public did initially think they’d come across human remains,” she said.

Overnight police faced challenging investigative conditions overnight, including chilly temperatures, heavy rain, and wind.