At least 13 suspects have been arrested for suspected manslaughter in a probe into the city’s deadliest fire in decades, pointing to substandard renovation materials for fuelling a blaze that has claimed at least 151 lives.

Police continued to sweep the seven burnt-out towers engulfed in last week’s disaster at the Wang Fuk Court estate, finding bodies of residents in stairwells and on rooftops, trapped as they tried to flee the flames.

Director of Hong Kong Fire Services, Andy Yeung, revealed that some fire alarms in the complex were found to be nonfunctional, saying there could be legal consequences once the investigation is complete.

Reports indicate that more than 40 individuals are still missing.

“Some of the bodies have turned into ash, therefore we might not be able to locate all missing individuals,” police official Tsang Shuk-yin told reporters.

Contractors working on the renovations used these substandard materials in hard-to-reach areas, effectively hiding them from inspectors, said Chief Secretary Eric Chan.