Forensic officers continued to work at a recycling plant where human bones were found at the weekend.
Blue forensic tents have been erected inside the Biffa waste processing facility on the outskirts of Hartlepool.
Cleveland Police said employees on site at Tofts Farm Industrial Estate called police at around 11.40am on Sunday after making the find.
Tests have proved that the discovery was human remains, prompting a police investigation.
Senior investigating officer Detective Inspector Chris Pringle, from Cleveland Police’s Homicide and Major Enquiry Team, said: “The investigation is in the very early stages and is extremely complex and sensitive due to the circumstances in which the remains have been found.
“We have a dedicated team of detectives and officers from departments across the force working at pace and conducting the investigation expeditiously to identify the remains; however, this will take a considerable amount of time.
“There are numerous procedures to follow to identify the remains and to establish the circumstances surrounding how they came to be at the recycling plant.
“I understand how concerning this will be for those living within our community and the wider public.
“I know there will be families who have missing loved ones and worried about the remains, and I want to reassure you that if any relevant information comes to light, we will be in touch.”
The recycling plant has been closed since the discovery was made.
A Biffa spokesman said: “Police were called after remains were found at the plant on Sunday, March 30.
“We are unable to comment on the investigation and the site remains closed until further notice.”
