'Possible human remains' have been discovered close to an abandoned pub in Bolton.
Police have cordoned off an area of woodland close to the building.
Tests and forensic analysis is currently being carried out to ascertain the circumstances of the incident, Greater Manchester Police said.
It is not believed that this incident is linked to any ongoing investigations, they added.
Two eyewitnesses say officers were called to the building, just off Blackburn Road, near Egerton Park, at around 12.20am.
Danny and Felicity Duffy have spoken of their shock after discovering what they claim was a human skull.
An army style jacket was also found close to the remains, they said.
The couple immediately dialled 999 to alert police.
Danny said they are “shaken up” by the discovery and were unable to sleep after police released them from the scene at around 3.30am.
“I’ve not slept,” Danny said. “I can’t get it out of my mind. I’ve never come across anything like that before.
“We both felt sad. Felicity has been quite upset.
“We’ve only slept for about an hour. As soon as I woke up I thought it was a bad dream.”
The couple - who run a paranormal investigation Youtube channel - were in the area filming when they made the sad discovery.
“We were doing our normal routine and about 10 or 15 minutes in we spotted something,” Danny says.
“There was a jacket on the floor. Then I saw what looked like a pebble on the floor.
“I moved the bushes to the side and it was a human skull in the tree line. It really did give us a shock.
“My legs turned to jelly. We rang the police straight away.”
He added: “A police van came down almost immediately and two officers came to the scene.
“We were sat in the back of the police van for almost four hours.”
A Greater Manchester Police spokesperson said: “Police were called at around 12.35am on Monday 1 March to a report of a suspicious item being found off Blackburn Road, Egerton.
“Officers attended and found possible human remains.
“Enquiries are ongoing and a scene is in place whilst tests and forensic analysis are carried out to ascertain the circumstances.
“No arrests have been made.
“There is no threat to the wider public.”
