Four Vietnamese men who died in a mill fire were likely to have been the victims of modern slavery, police have said.
The men’s bodies were discovered 10 weeks after a huge fire destroyed the derelict Bismark House Mill in Oldham, Greater Manchester, on 7 May.
Greater Manchester police said it believed part of the mill was being used as an illegal cannabis factory before the blaze.
Det Supt Lewis Hughes said: “It’s safe to say that we believe they were likely to have been the victims of modern slavery.
“If we are looking at them being the victims of organised crime or exploitation there are people that will be spoken to and people on bail already.”
Hughes said detectives were investigating “modern slavery offences, organised crime offences” and potential murder as part of the inquiry into the deaths. The men were all identified through DNA samples recovered from the collapsed building.
One of the men, Nam Thanh Le, 21, had arrived in Britain just eight months before the fire and told relatives he was living in a “mill” in “Dam” – believed to be Oldham – while looking for work. He last contacted his family three days before the blaze.
The family of another of the men, Cuong Van Chu, 39, said earlier this month that they were “devastated at his tragic death in the most terrible circumstances”. The other two victims have been confirmed as Uoc Van Nguyen, 31, and Duong Van Nguyen, 29.
Two men who were arrested on suspicion of manslaughter and other offences in connection with the case were released on bail earlier this year.
Hughes told the Manchester Evening News: “They are still on bail and there is ongoing work to better understand their involvement.
“There are other lines of inquiry at the factory and it’s safe to say we have recovered evidence that cannabis was being cultivated in part of the factory.”
Firefighters spent four days tackling the blaze, which started on 7 May in what was thought to be an empty mill. It was not until 23 July that the men’s remains were found by workers demolishing what was left of the site.
An inquest was opened and adjourned at Rochdale coroner’s court earlier this month pending the outcome of the criminal investigation.