LONDON — British police investigating the fire at Grenfell Tower in which 79 people are believed to have died say the blaze started in a refrigerator’s freezer. They added that insulation and tiles recovered from the building have failed fire safety tests.

Police say manslaughter charges are among actions being considered as they review potential safety violations.

Metropolitan Police Detective Supt. Fiona McCormack says authorities are “looking at every health and safety and fire safety offense and we are reviewing every company at the moment involved in the building and refurbishment of Grenfell Tower.

“What we are being told at the moment by the Building Research Establishment is that the cladding and insulation failed all safety tests,” she told reporters Friday.

Downing Street has ordered an immediate examination of the model of refrigerator that is believed to have sparked the fire.

McCormack said the Hotpoint FF175BP fridge-freezer had not been subject to any product recall.

Eleven buildings have now been identified as having combustible cladding such as that used on the tower.

Fears about the cladding are not limited to apartment buildings, and at least one hotel chain is calling in experts to make certain it meets safety regulations.

McCormack repeated calls for anyone with information on who might have been in the tower to come forward. The call comes after London Mayor Sadiq Khan’s pledge to seek an amnesty for people who may have been living in the tower illegally.

“What we haven’t got is a picture of how many people might have been in there,” she said. “That’s the number I’m really worried about.”

She said that all of the bodies that were intact have been removed from the 24-story tower block and that the death toll remained at 79.

“However, I do expect the number to change,” she told The Washington Post.

This story will be updated.