Police said on Tuesday they were investigating six reports that some housing estates had used falsified documents for scaffold nets installed during maintenance works.

The estates are Baguio Villa in Pok Fu Lam, Fung Wah Estate in Chai Wan, Fortress Garden in North Point, Yee Kok Court in Sham Shui Po, Ching Lai Court in Cheung Sha Wan and Marigold Mansions in Hung Hom.

Nets that were not resistant to fire have been identified as one reason for the rapid spread of the blaze that engulfed seven of Wang Fuk Court's eight blocks in Tai Po last month.

There have been claims that some estates used scaffold nets that failed safety standards while relying on fake certification documents to pass checks.

The government had ordered all buildings under major-maintenance works that require the use of scaffold nets on external walls to take them down by last Saturday as a precaution following the devastating fire in Tai Po that took the lives of 159 residents.

The Buildings Department said 227 private buildings had already taken down the nets. The removal process in three remaining cases – which have been granted deadline extensions – is under way and expected to finish within this week.

It added that it planned to roll out new rules this week that require samples to be taken from construction sites and checked to ensure that scaffold nets meet safety standards before they could be installed.

Once the new rules are in place, external wall works can restart as soon as possible, it said.