Authorities in Hong Kong have ordered the removal of scaffolding mesh from buildings undergoing renovations by Saturday, as investigations continue into the Chinese territory's deadliest blaze in decades.

It is now known that 159 people died as a result of the fire last Wednesday at the Wang Fuk Court housing complex - with 31 still missing.

Investigators have found that a protective netting used around the complex, which had been undergoing extensive renovations, failed to meet flame retardant standards.

Secretary for Development Bernadette Linn Hon-ho said new guidelines for testing materials used in scaffolding would be issued next week.

Around 200 private residential and 10 public buildings are currently undergoing renovations in Hong Kong. The South China Morning Post reports that about 300 buildings will be affected by the removal order.

I assure the public that we will chase to the end the accountability of any contractors using substandard scaffolding mesh, Linn was quoted as saying. Samples had already been taken from mesh for testing, she added.

At Wang Fuk Court, flames spread quickly across the separate tower blocks on protective mesh netting and other flammable materials on the outside of the buildings, officials said.

Police have made at least 15 arrests for manslaughter as the investigation into the cause of the fire proceeds. They have completed their searches of the interiors of all seven of the complex's towers and will now look for bodies in other parts of the buildings.

Among the deceased, 140 of the 159 bodies have been identified, including 49 males and 91 females, aged between one and 97.

A married couple in their 70s, who lost their home in the blaze, expressed their helplessness as they witnessed the fire spreading uncontrollably.

It all happened within just an hour or two... I felt completely helpless. I still don't understand how the fire could spread so fiercely, the mother recounted.

As investigations continue, officials aim to uncover any potential negligence or hidden causes behind the disaster.