Hong Kong leader John Lee apologised on Thursday after an independent investigation into the city's deadliest fire in decades found shortcomings in regulatory supervision, announcing that Housing Secretary Winnie Ho had resigned over the incident.

The massive blaze broke out last November at Wang Fuk Court, a residential complex in a northern suburban district, engulfing seven buildings and killing 168 people. Thousands of residents were displaced by the disaster.

Nearly a year later, former residents have been waiting for answers about accountability for the tragedy, which destroyed their homes and claimed the lives of their loved ones while the apartment complex was undergoing maintenance work.

At the beginning of a news conference, Lee and seven other senior officials bowed to express their apologies. Lee said Ho should take political responsibility for the incident, although the investigation found no personal wrongdoing on her part. He confirmed that she had resigned on Wednesday.

An independent committee investigating the disaster found that the Housing Bureau's independent checking unit had failed to properly carry out its responsibilities in overseeing the maintenance work.

The committee's findings are separate from ongoing criminal proceedings in which seven individuals and two companies have been charged with offences, including manslaughter and conspiracy to defraud, in connection with the fire.

Authorities alleged that the companies and some of the defendants conspired to mislead apartment owners by concealing the previous litigation history of a company that was later awarded the renovation contract.

The contract was valued at more than 300 million Hong Kong dollars, equivalent to over $38 million.