A property project by Country Garden Holdings Co Ltd in Zhenjiang, Jiangsu province, attracts homebuyers.[Photo/China Daily]

Four six-square meter apartments sold this weekend in Shenzhen made a splash in the media, but the sales were later declared illegal due to unauthorized modifications made to the properties.

Nicknamed "pigeonholes", these mini studios are located in a 15-story building called Qiaocheng Shangyu, which offers 11 apartments at sizes ranging from 5.73 to 7.48 square meters, and 160 other units of 35 to 45 square meters.

But the Urban Planning, Land and Resources Commission in the city's Nanshan district on Monday said the actual size of these four apartments ranged from 12 to 20 square meters after illegal changes were made to public shared areas.

The district's supervisory bureau of land planning on Monday forced the managers of the property company to demolish the illegal constructions, cancel the four trading contracts, and suspend all sales activities.

The district's authority said four real estate agencies－Homelink Real Estate Brokerage Co, Midland Realty, Centaline Property and Qfang.com－are also being investigated for illegal dealing.

Though the size of these apartments is extremely limited, they were fully furnished as a complete home with kitchen, bathroom, one folding bed and about three windows.

Besides their size, another attraction was their location－just a street away from the Shenzhen High-Tech Industrial Park, which hosts most of the city's technology companies, and a few minutes' walk to shopping center and metro station in Nanshan, the city's most expensive residential district.

These mini homes were sold at a fixed price of 880,000 yuan ($133,330), much more affordable than normal sized homes in the same district, which retail for millions or even tens of millions yuan, due to local skyrocketing home prices.

Song Ding, director of the Tourism and Real Estate Industry Research Center at China Development Institute, a Shenzhen-based think tank, said the existence of such tiny apartments is a necessary outcome of Shenzhen's rocketing home prices, which have become one of the nation's highest and fastest growth.

The average price of new houses in Shenzhen reached 57,728 yuan per square meter in August, an increase of about 60 percent compared with last year, according to the city's Urban Planning, Land and Resources Commission.

Song said that some residents now cannot even afford a small-size house of 50 to 60 square meters in downtown or ones an hour's drive away from where they work.