The criminal investigation into the deaths of four men who died at the burnt-down Bismarck House Mill in Oldham will take "some time", an inquest hearing has heard.

Today (June 9) at Rochdale Coroners Court, senior coroner Joanne Kearsley held a pre-inquest review hearing into the deaths of the four Vietnamese nationals who died in the fire last year.

The court heard how the bodies of the four men were identified, while updates on the Greater Manchester Police investigation into the circumstances were provided.

Uoc Van Nguyen, 28, Cuong Van Chu, 39, Duong Van Nguyen, 29, and Nam Thanh Lee, 21, were previously named as the four victims of the blaze in May 2022.

Detective Superintendent Lewis Hughes told the court that so far, four people had been arrested in relation to the fire and deaths, all of whom had been released on bail. GMP is yet to formally charge anyone.

DSI Hughes said a large number of warrants had been executed as police investigate to see if the fire and deaths were connected to organised crime, the cultivation of cannabis and modern slavery.

He agreed with Ms Kearsley's understanding that the investigation is likely to take "some time" before it concludes.

The court heard how the bodies of the men were identified through mechanical matching of forensic anthropologists.

The anthropologists used bone fragments found at the site, which were compared to DNA samples from members of the victims' families in Vietnam, obtained by a team from GMP.

DSI Hughes and Ms Kearsley both said they were satisfied all the bodies had been identified and were content that they could be released in order to be returned to the families in Vietnam.

The bodies will be cremated in the UK before being sent back due to health and safety reasons along with it being the wishes of the families.

Ms Kearsley said she was still awaiting reports from a pathologist which would confirm the medical cause of death.

She concluded the hearing by praising the efforts of those who helped recover the remains of the four men from the scene, saying that acted with "dignity and compassion".

Ms Kearsley said the case was "one of the most complex and challenging investigations conducted in the UK for a long time" and that those on the site had spent six months working through 5,000 tonnes of rubble.

The inquest was adjourned until the conclusion of the criminal investigation, with the next hearing to take place in November when matters regarding the case are reviewed.