The sudden death of a migrant worker while hunting for porcelain pieces highlights the risks people take looking for buried treasure in the construction sites around Beijing.

Yang Hailong, 36, from Hebei province, was a professional "porcelain hunter", who sneaked into a construction site near Wangfujing with his cousin at midnight on Nov 27. He was buried and killed when the clay pit he was in suddenly collapsed.

"We just wanted to make a living," Yang Haidong, his younger brother told METRO on Wednesday.

Yang said they began hunting for porcelain after a visit to Panjiayuan, the city's famous antique market, when they arrived in Beijing two years ago.

"It is dangerous. But it is also special. If somebody is really good at it and lucky enough, they can gain large rewards by doing it," he said.

The profession of "porcelain hunter" began in the 1990s in cities like Nanjing, Xi'an and Beijing, and now there are at least 100 people in Beijing who do it professionally, as well as some construction workers who do it part time. There are more than 100,000 collectors of porcelain nationwide, according to Beijing Youth Daily.

Wang Yi, a vendor who owns a stall in Huguo Temple, told METRO that quite often construction workers or professional porcelain seekers come to sell him the porcelain pieces they found or excavated.

The temple holds a regular antique market where art lovers can sell or trade porcelain pieces and other treasures.

"Others may treat the pieces as useless garbage, but for antique enthusiasts, they are real treasures," Wang said.

Some rare pieces of porcelain can sell for around 1,000 yuan or more, Wang added, although small fragments usually sell for 5 yuan a piece or 150 yuan a bag.

"At any construction site within the Second Ring Road, there will be porcelain pieces buried underground," Wang said, referring to the fact that Beijing was the capital during the Ming (1368-1644) and Qing (1644-1911) dynasties when porcelain pieces were part of daily life for many.

"If an ancient garbage dump is buried near the construction site, the potential for discovering a large quantity of porcelain pieces is tremendous," he said.

But in order to find this potential fortune, professional porcelain hunters must either buy the pieces from construction workers, or take risks and sneak into construction sites at night to dig.

Such a situation is quite prevalent in Beijing's construction sites, according to Shan Lei, a porcelain lover who has been collecting porcelain for seven years.

Shan added that, as the art market is booming, so is porcelain hunting. But he cautioned that it's quite possible that a large proportion of the porcelain pieces in the market are fakes.

The digging up and trading of porcelain also raises concern about the protection of underground relics.

According to the city's current regulations, large construction sites are required to carry out archaeological investigations before starting work.

But according to figures released last year, of the more than 4,000 construction projects launched in Beijing in 2008 and 2009, only 2.3 percent were the subject of thorough archaeological surveys. And there is no punishment even if the developers do not cooperate to do the archaeological survey. As a consequence, the damage done to Beijing's underground relics is becoming more and more serious.

Zhu Naicheng, director of the Archaeological Information Center of the Chinese Academy of Social Sciences, also pointed out that, lacking proper skills and using simple tools, the treasure hunters' digging always has a negative impact on archaeological excavations.

"If some ancient tomb is buried under the construction site, their reckless behavior will have an irreversible impact on our excavations and research,"

he told METRO.

And, just like tomb raiders, porcelain hunting is not only dangerous and irresponsible it is also illegal, according to Zhao Heng, a lawyer with Beijing Yingke Law Firm.

"China's Law on the Protection of Cultural Relics makes it very clear that all the cultural relics underground belong to the nation rather than the individuals.

"So the digging is illegal," he said.