One hundred social-housing tower blocks in London face even worse fire risks than Lakanal House in Camberwell, where six people died in July, says the BBC.
It claims that councils have failed to fire check at least 253 social housing high-rise buildings - which is a criminal offence.
A BBC London team found that while Lakanal House had been given a medium-risk rating on a scale used by councils, thousands of residents live in accommodation condemned as high risk.
One of the worst boroughs is Hounslow, where 21 of 37 towers rated high risk face dangers described as “off the Richter scale” by a surveyor who was part of a BBC investigation.
Meanwhile, ten boroughs admit to having one or more high-risk towers, meaning that they are likely to experience “an extremely harmful event”.
Other boroughs with large numbers of high-risk towers include Barnet, Redbridge, Havering, Haringey and Greenwich.