Human remains have been discovered following a fire at a mill in Oldham - two and a half months ago.
Greater Manchester Police (GMP) say it received a report on Thursday, 21 July, that four Vietnamese nationals were missing and may have been involved in a fire.
Demolition workers later found remains at Bismark House Mill, on Saturday 23 July, leading to the the force declaring a major incident.
It is believed just one body has been found - but officers say there could be up to four.
Detective Superintendent Lewis Hughes, from GMP, said: "So far we have found what we believe to be human remains that may be relevant to one person.
"But we are working under the hypothesis that the information we have suggests there maybe up to four people involved.
"There maybe more than four, or less than four, it is simply premature to tell."
A huge blaze tore through the building on 7 May 2022, which took firefighters four days to extinguish.
Police say it was not believed that anyone was inside the mill at the time of the fire.
Forensics, as well as officers from GMP, fire crews and the Urban Search and Rescue teams are at the scene conducting enquiries.
Det Supt Hughes said the force had been made aware of the missing Vietnamese nationals from information "via Vietnam", which had been passed through intermediaries and then on to police.
"Our thoughts go out to the bereaved families of the individual, or individuals who are going to be involved in this incident who have tragically lost their lives in whatever may have taken place here," he added.
Assistant Chief Constable Rob Potts said: "Victims and the bereaved are at the forefront of our investigations into deaths.
"As such, whilst work is ongoing to confirm the identity of the deceased, we are liaising with partner agencies to ensure potential family members in Vietnam are fully informed and supported.
“This news will understandably impact both the local and wider community. I can reassure members of the public that this has been declared a major incident to ensure both GMP and partner agencies respond to this incident in the most effective way and that specialist officers are following every line of enquiry to confirm the identity of the deceased, if anyone else was inside the mill during the fire, and the full circumstances surrounding that fire.
“Any criminal offences identified as part of their investigation will be immediately and appropriately progressed."
The incident has now been referred to the force’s Professional Standards Branch for review due to previous contact relating to the fire and missing persons.
Speaking to media at the site, Assistant Chief Fire Officer for Greater Manchester Fire and Rescue Service Leon Parkes said: “When the fire service arrived at the scene they were met with a very serious fire, a well-developed fire, in the building.
“A decision was made at that time not to permit any firefighters into the building for two reasons – firstly, the fire was well-developed and was continuing to grow and, secondly, there was some concern about the structural stability of the building.
“We fought the fire over four days from the outside before handing the premises over.
“These are the correct procedures that are followed in situations like this.
"Given the devastation that has happened here it is right that we are absolutely certain and that is why we are now reviewing the details of the incident and how we managed the incident."
Mr Parkes said it appeared the site of the blaze was a multi-occupancy warehouse used by a number of companies.
The building was thought to be locked up and closed when the fire broke out in the early hours, he added.
"Our firefighters who attended this incident will be devastated by what has transpired," he said.
Anyone with information, particularly anyone who knows how the building was being used in the lead up to 7 May or who has information about the fire itself, can submit it to police via the Major Incident Public Portal or call 0161 856 0055 quoting Operation Logan.
Information can also be shared anonymously via the independent charity, Crimestoppers on 0800 555 111.
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