The badly decomposed body of a woman was found by a bushwalker about 12.30pm on Monday in the Macedon Regional Park north of Melbourne, the Bendigo Advertiser reported.

The scene is not far from an area where police searched for missing Avondale Heights woman Karen Ristevski in December.

Police said on Tuesday morning they do not expect results from a forensic examination until at least Wednesday.

State Emergency Service volunteers and homicide squad detectives returned to the scene, where a line search is expected to be conducted.

The area at the corner of Salisbury and Loch roads, a hilly single-vehicle track, were sectioned off by police on Monday. It appeared the body, found between the trunks of two fallen trees, was discovered only about 50 metres from Loch Road, close to houses and a kilometre from Mount Macedon Primary School.

The bush around where the body was found is not heavily wooded or overgrown, making it easy to walk through. But the height of the fallen trunks would have made it impossible to see the remains unless you were standing directly above them.

The body was removed from the scene late on Monday night to undergo testing.

Forensic investigators and homicide squad detectives spent more than eight hours working at the site.

"The remains will be taken for forensic testing to determine the identity of the deceased and the cause of death," a police media spokesman said on Monday.

Police worked through the afternoon and into the night on Monday, with the coronial service arriving after nightfall and removing the remains about 10.30pm.

It is understood the body was escorted to Melbourne by a number of detectives.

On Monday dozens of journalists and photographers gathered at the scene watching from afar as investigators, some with shovels, worked among thick undergrowth.

About 6.45pm, a couple turned up at the scene and told officers they had previously seen a man in the area with a shovel and made a joke to him about burying a body.

After recounting the story to uniformed officers, the couple was taken away from the media contingent to behind the police cordon.

Locals Krystal Pate and Alastair McLellan visited the scene on Monday afternoon and said the entire area around Mount Macedon was a very popular place for hikers.

However, they said they didn't realise the road near where the body was found went so deep into the forest.

"I thought it was a no-through road until today," said Mr McLellan.

"Though you would have your local people going for walks around here." 

Resident Paul Gordon said walkers avoided the bush track, near where the body was found, because it was so rough.

Ian Flannery said "very, very few people at all" ventured into that part of the bush.

"You might see a couple of walkers, maybe a four-wheel-drive driven down every now and then, but it's very, very isolated."

In December, police looking for Ms Ristevski searched dams and grassland in Toolern Vale, about 25 kilometres from where the body was found on Monday.

However, it is not known if the case is linked.

Ms Ristevski, 47, was last seen at her Avondale Heights home by her husband Borce Ristevski on June 29, 2016.

There have been reports Ms Ristevski's phone pinged on towers on the Calder Highway and at Gisborne on the day she went missing.

Police and SES volunteers searched an area from Blackhill to Gisborne roads, looking in grassland, waterways, creeks and farms on December 19 and 20.

Mount Macedon is a 23 minute-drive from Toolern Vale, and a 15 minute-drive from Gisborne.

Fairfax Media understands the Ristevski family is aware of the discovery, but has not been formally notified by police.

Ms Ristevski's husband, Borce, told a reporter from Channel Nine's A Current Affair program that he was unable to make any comment as he thought his phone was tapped and police were listening.

- With Emily Woods and Adam Holmes

Area in Macedon where body was discovered yesterday...Near where Police searched for Karen Ristevski @TheTodayShow pic.twitter.com/NOyfsX9yol— Christine Ahern (@ChristineAhern) February 20, 2017