Cage dogs of Hong Kong: The tragedy of tens of thousands living in 6ft by 2ft rabbit hutches - in a city with more Louis Vuitton shops than Paris

Hong Kong, one of the world's richest cities, is abuzz with a luxury property boom that has seen homes exchanged for record sums.

But the wealth of the city has a darker side, with tens of thousands priced out of housing altogether and forced to live in the most degrading conditions.

These pictures by British photographer Brian Cassey capture the misery of people - some estimates put the figure as high as 100,000 - who are forced to live in cages measuring just 6ft by 2 1/2ft.

Yan Chi Leung is mentally ill and lives in the 6ft by 2.5ft wire cage at the bottom of this stack of three

Kong Sui Kao, 64, sits in his home in a room with 19 other cages

The city is one of the planet's most densely packed metropolitan areas, with nearly 16,500 people living in every square mile of the territory.

Unscrupulous landlords are charging around US$200 a month for each cage, which are packed 20 to a room, and up to three levels high.

The lower cages are more expensive because you can almost stand inside them, but the conditions are no less squalid.

All this in a city with more Louis Vuitton shops than Paris.

Tai Lun Po, 79, has lived in the cage he is sitting in for an extraordinary 30 years

Eight-year-old Lee Ka Ying lives in a 6ft square 'cubicle cage home' with her mother

Yan Chi Keung eats takeaway outside his wire cage home - there are no cooking facilities

Tai Lun Po walks to the bathroom which he shares with the other residents

Occupants must share toilets and washing facilities, which are rudimentary. Many of the apartments have no kitchens, forcing their impoverished residents to spend there meagre incomes on takeaway food.

The cage homes have been a running scandal in Hong Kong's housing market for decades, yet rather than disappear, they are on the rise.

As the world economic crisis has lashed the city a former British territory whose economy is focused on financial services, more have been forced to turn to them for a place to stay.

The alternative is life on the streets.

Mr Yan smokes a cigarette amid his neighbours in his cage flat

Tai Lun Po walks the corridors of his Mongkok Hong Kong cage home

Tang Man Wai, 60, a retired restaurant worker, is forced to spend what little money he has on take-away food

A building in Mongkok that houses cage people, sometimes squeezed twenty to a room

One cage dweller, Cheung, who lives in Sham Shui Po, told the Asia Times Online he endures appallingly cramped and fetid conditions.

'The temperature inside the cages can be two to three degrees higher than what they are outside,' he said.

'It's really uncomfortable, and sometimes I cannot sleep until after 5 in the morning.'

Cockroaches, wall lizards, lice and rats are common. 'Sometimes I am worried if lizards or cockroaches will crawl into my ears at night,' said Cheung.