Residents of a smart Clapham building once lived in by Dame Vivienne Westwood said this week they were shocked a man was allowed to die there in squalid conditions.

Thurleigh Court, a 1930s art deco building where the world-renowned designer owns a flat, was the scene of Mayan Coomeraswamy’s lonely death earlier this year.

Residents said the Nightingale Lane building was crammed with modern flats for young professionals, who prided themselves in a strong community atmosphere but had no idea what was happening on their doorsteps.

Sian Robertson, a 25-year-old personal relations manager, said: “It’s really shocking, I haven’t heard of this at all, and I have been living here for two years. If something is going on, usually everyone hears about it.

She added: “There was a really crazy man on our floor- but he seemed nice and said hello. I think that could have been him.”

Many of the flats have been refurbished to a very high standard, and the carpark holds an impressive array of expensive cars.

Last year Dame Westwood joined residents in a campaign to stop the building being redeveloped, citing its historical importance.

Her son, the erotic photographer Ben Westwood, still stays there regularly with friends.

On Thursday an inquest at Westminster Coroner’s Court heard Mr Coomeraswamy was found dead just a few doors away on January 9.

The coroner, Dr Paul Knapman, described his flat as “barely fit for human habitation” as every room was filthy and the boiler was not working.

A post mortem report showed signs of hypothermia.

The landlord wanted to clean the flat for some years, but care workers refused to forcibly move him to allow the work to take place.

The court was told they feared his human rights would be violated.

The case has triggered a review into how South West London and St George’s Mental Health Trust handles vulnerable patients choosing to live in such conditions.

The results of the review could affect adult care policy nationally, and will be disclosed at the inquest’s next hearing, on Wednesday, December 9.

Alex Webster, 23, a friend of Ben Westwood staying in his flat this week, said: “There’s a lot of this going on. You have got a city of 8 million people.

“How can you get a handle on every single person’s life without having a big brother state?”