The November 26 blaze at Wang Fuk Court, a high-rise apartment complex in the financial hub's Tai Po district, was the world's deadliest residential building fire since 1980.

It engulfed seven of the eight residential towers in the complex, which were undergoing renovations and covered in bamboo scaffolding, protective netting and foam boards that may have contributed to the fire's rapid spread.

"We want to know the causes of the disaster and the responsibility (who is to blame). At the very least, we need to know what caused the fire and why it spread so rapidly, becoming completely uncontrollable," former resident Seneca Lee told reporters outside the court.

"I believe ?this disaster) was not caused by just one or two factors," she said.

A 69-year-old man who gave only his surname Law said he had lived at Wang Fuk Court for more than three decades.

"The thing I most want to know is why the fire alarms did not sound. They did not sound throughout the whole estate. That doesn't make any sense," Law said.

"I have a relative who passed away, so I'm feeling down."

Witnesses expected to appear at the hearings include government officials, former residents, the directors of construction firms and members of the Wang Fuk Court management committee.

Yip Ka-kui, who lost his wife and home in the blaze, told AFP that he wanted "justice for the deceased and an explanation for the victims".

"I hope the independent commission will truly investigate everyone involved, and clarify what responsibility they hold," he said.

"They should take responsibility if they are at fault."

The judge-led committee will investigate whether fire safety standards were inadequate, if construction practices contributed to the fire, and if there were failures by government officers or contractors.

The committee's website said it would also seek to determine whether there were more systemic problems that included "conflicts of roles, or improper collusion... and whether bid-rigging corruption, or irregularities were involved in the tendering process of these works".

Police are conducting a criminal investigation and have arrested 38 people on charges including manslaughter and fraud.

Hong Kong's anti-graft watchdog has also arrested 23 people, including consultants, contractors and members of the owners' corporation of the complex, the Independent Commission Against Corruption said in a statement on Wednesday.