Updated

Workers scaled an apartment building in Beijing on Friday to demolish a bizarre rooftop villa which captured worldwide attention but was deemed illegal by Chinese authorities.

At least six workers wearing bright orange jackets were visible on the 26-storey building's roof and were dismantling the elaborate house, which was built among rocks and trees.

Work began on Thursday after the villa's well-connected owner hired a team to start dismantling it, the Beijing Youth Daily reported, following intense media scrutiny of his business activities.

"I'm very angry that the departments responsible didn't take any action for years, but this is a good start," said a 70-year-old woman surnamed Teng, who lives in a building opposite.

"It's a good thing that demolition has finally started," she told AFP.

Authorities on Monday said the brazen structure -- which began springing up six years ago -- was illegal and threatened to demolish it after 15 days if its owner did not remove it.

The owner, Zhang Biqing, founder of a national chain of acupuncture clinics and a former member of a district-level political advisory body, had threatened neighbours who complained about the construction, reports said.

International and local media attention on the building has been intense, with Chinese web portal Sina using an aerial camera to swoop over it, revealing a multi-tiered construction heavy with vegetation and with several security cameras.

"We resolutely support major media outlets in revealing this residential compound's illegal structures," read a red banner placed on the fence of the building's compound, apparently written by residents.

But some were less supportive of the demolition.

"It's something an ordinary person would never usually build," said 63-year-old local resident Tan Huiqin.

"It's a bit of a shame that it's being demolished... I'm not sure if it is truly dangerous."

Taxi driver Jin Jian was clearly impressed.

"It's an awesome structure," he said as he waited opposite the building.

The rooftop villa has focused attention on the issue of illegal construction in China, with local reports saying that Zhang's connection with celebrities and government officials had given him a sense of impunity from the law.

But some locals were sceptical about whether all of Zhang's roof-top additions would be removed.

"It won't be demolished completely," said one middle-aged man who sat on a motorcycle outside the building, but declined to give his name.

"He must have good relationships (with authorities), he's even had celebrities to sing karaoke in the villa," he said.