A man who made his fortune in traditional medicine spent six years building his own private mountain peak and luxury villa atop a high-rise apartment block in China's capital. Now, authorities are giving him 15 days to tear it down.

The craggy complex of rooms, rocks, trees and bushes looming over the 26-storey building looks like something built into a seaside cliff, and has become the latest symbol of disregard for the law among the rich as well as the rampant practice of building illegal additions.

Angry neighbours say they have complained for years that the unauthorised, 800 sq ft mansion was damaging the building's structural integrity and its pipe system, but that local authorities failed to crack down. They had also complained about loud, late-night parties.

"They've been renovating for years. They normally do it at night," said a resident on the building's 25th floor, who added that any attempts to reason with the owner were met with indifference. "He was very arrogant. He couldn't care less about my complaints," said the neighbour, who declined to give his name to avoid repercussions.

According to local media, the villa has been under construction for the past six years and comes complete with fake rockeries and landscaping. Photograph: How Hwee Young/EPA

Haidian district urban management official Dai Jun said on Tuesday that authorities would tear the two-storey structure down in 15 days unless the owner does so himself or presents evidence it was legally built. Dai said his office has yet to receive such evidence.

The villa's owner has been identified as the head of a traditional Chinese medicine business and former member of the district's political advisory body who resides on the building's 26th floor. Contacted by Beijing Times newspaper, the man said he would comply with the district's orders, but he belittled attempts to call the structure a villa, calling it "just an ornamental garden".

China illegal construction of villa on rooftop of residential building Photograph: How Hwee Young/EPA

Authorities took action only after photographs of the villa were splashed across Chinese media on Monday. Newspapers have fronted their editions with large pictures of the complex, along with the headline: "Beijing's most outrageous illegal structure."

The case has resonance among ordinary Chinese who regularly see the rich and politically connected receive special treatment. Expensive vehicles lacking licence plates are a common sight, while luxury housing complexes that surround Beijing and other cities are often built on land appropriated from farmers with little compensation.

China's leader Xi Jinping has vowed to crack down on official corruption, and Beijing itself launched a campaign earlier this year to demolish illegal structures, although the results remain unclear.

Demand for property remains high, however, and the extralegal rooftop mansion construction is far from unique. A developer in the central city of Hengyang recently got into hot water over an illegally built complex of 25 villas on top of a shopping centre. He later won permission to keep the villas intact as long as they were not sold to others.

While all land in China technically belongs to the state – with homebuyers merely given 70-year leases – the rules are often vague, leaving usage rights and ownership murky.

A city in Sichuan province recently caused a minor stir when it was discovered to have cut the length of land leases from the normal 70 years to just 40 years.

The local government's response to public queries drew even more jeers. Officials posted a statement online maintaining that the law allows for lease periods of less than 70 years and added: "Who knows if we'll still be in this world in 40 years. Don't think too long-term."