Spring comes quickly in Beijing and nowhere is the thaw more visible than at the opening day of a main event in one of the country's hot new industries - the China Guardian Spring 2005 Auction.

At the basement entrance of the Kunlun hotel, crowds of dealers and collectors jam through revolving doors and funnel up an escalator into the foyer above. At the top of the moving stairs, company deputy managing director Kou Qin is on hand to greet them.

China Guardian is the largest and oldest of the mainland's estimated 4,000 auction houses and its spring and autumn events are the biggest on the industry calendar.

At the preview, Kou is standing in front of the first item on show - a three-metre painting of Mao Zedong under the guns of a battleship by the artist Ai Minyou. To his right, a line of similarly imposing portraits of the Chairman. Nearby are vibrant contemporary canvasses and sculptures. In other areas more traditional items fill display booths and glass cases.

Sourced from both domestic and overseas collections, works of calligraphy, ink landscapes, jade carvings, bronze statuettes, fine porcelain, antiques, ancient coins and bronze mirrors, stamps and rare books squeeze into every meter.

Eager bidders must make the most of this first of three preview days to inspect any items that arouse their interest. There is serious business to be done in the auction proper that follows at the weekend. Once bidding starts, more than five thousand pieces will go under the hammer.

"Our turnover at this event has increased 25 times since we started it a decade ago,'' says Kou. "Transactions for last autumn's auction were more than double the year before. We're hoping for a similar increase this time too.''

This flagship event is just one part of an exploding industry. In 2004, figures from the Chinese State Cultural Relics Bureau show, legal sales of relics at auctions nationwide topped 3.9 billion yuan (HK$3.67 billion) - of which Guardian took more than a quarter - more than triple the previous year's volume. Experts estimate that market prices for artworks and relics have doubled in three years.

China Guardian's 2005 spring auction ended on May 15 with sales totaling more than 600 million yuan, well over double the volume for last year's event and more than 40 times the volume of China Guardian's first spring auction in March 1994.

As with so many things in China, breakneck expansion has come at a price. China's auction market is like a chaotic frontier with abundant opportunities for con-artists, thieves and forgers.

Given China's inflated real estate, the low quality of its stock markets and a ban on transferring money overseas, it might appear that the frantic art and antique trade is due in large part to a lack of alternative investment vehicles. Kou disagrees, instead preferring to see it as proof of a deeper transformation in society.

"When people have satisfied their basic economic needs they are free to enjoy life's higher pleasures,'' he says. "It's not just dealers and professional collectors you see here today, but also normal middle-class people with enough surplus wealth to satisfy their need for cultural development.''

Certainly, Guardian's spring event is more than just a healthy display of economic well-being and home-grown culture. This is as true of the startling avant-garde paintings on display as it is of the more traditional shanshui (mountain-water) silk-mounted ink paintings and calligraphy.

Kou takes pleasure in pointing out that 30-40 percent of the lots in this year's auction were sourced through Guardian's offices abroad, often from second-generation overseas Chinese, delighted to see a parent's collection return to its homeland. After almost two centuries of turmoil and economic decline resulted in relics fleeing the country, the exodus has been reversed.

"When a people have been resurrected they will affirm their culture,'' says Xu Longseng, a goateed dealer from Shanghai.

"In England you may have collectors who know a lot about Chinese art, but it's not in their blood,'' says Zeng Yuanlin, a collector from the country's ancient capital of Xian. "Western clothes look better on West-erners, it's their heritage. Similarly, our appreciation is an ability that has passed through generations.''

In reporting on the phenomenon, mainland newspapers have even told of aging overseas Chinese collectors shedding tears of joy to know their Qing dynasty ceramics will not have to go to New York, London or Hong Kong because a good price can now be fetched at home. The same collectors might be less than ecstatic over the issue of fakes, however.

Dealers will tell you that at least 90 percent of antiques to be found in street markets have been artfully knocked off and exhibitions of the most skilfully contrived pieces are common.

Craftsmen in China traditionally learn their skills from imitating the works of others and forgeries showing up at auction are a regular occurrence as a steady stream of recent stories in the mainland media will attest.

On September 7 last year, for example, the Guangdong magazine Xinxi Shibao reported on a sale staged by the Guangdong Zhongyi Auction Company. Halfway through, bidding for a painting was halted when a son of the artist Zhou Yansheng stood up and declared that his father had never produced such a work.

After the Zhou family presented the company with a list of demands - including the identity of the seller to facilitate prosecution - the manager of the event was forced to resign.

When the Liaoning Mingcheng Company advertised an auction it was staging in April as "entirely guaranteed,'' the move was described as groundbreaking in the local media. In hindsight this seems ill-advised.

Five days later the provincial newspaper Nongyang Jinbao reported that the well-known artist Song Yugui had attended the auction preview himself, declared 12 paintings attributed to him there to be fake, and was initiating legal proceedings. A subsequent investigation by two experts concluded that works by three other artists on display were also forged.

Contacting an artist or his or her family for verification prior to auction seems a basic professional procedure. Not only provincial auction houses but also one of the big five national ones - Rongbao Auction Company - neglected to do this.

On January 17, the Beijing Youth Daily reported that a picture due to be sold at the house's pre-spring auctions had been declared a forgery by the artist Han Meilin, who went on to make the same accusation concerning 12 other paintings attributed to him that Rong-bao sold over the previous year.

The Han Meilin episode and others like it recently prompted the specialist mainland journal China Art News to declare the country's art auction industry to be "facing a crisis of confidence.''

"Under the law, auction companies have no obligation to guarantee the authenticity of the works they are selling so I say we are facing a crisis,'' says Qiu Zhengang, the journalist who wrote the article. "More than this, it's a problem about self-regulation and ethics within the industry.''

At the China Association of Auct-ioneers (CAA), deputy secretary Wang Fenghai denies any such crisis. "If it were true we wouldn't be seeing a gradual shift in the center for auctions of Chinese artworks and relics away from abroad; away from Hong Kong and towards Beijing,'' he says, although most foreign experts would deny the reality of such a shift.

"It's because mainland auctions are by and large up to standard. Everybody has confidence, and that's why the move is taking place.''

Wang denies that a dearth of expertise has resulted in the appearance of fakes at auction or other mishaps.

But when responding to suggestions that some of the 1,167 auction companies the CAA represents may be operating without a license - for which staff members must obtain a professional qualification - his denial is less than categorical.

"I should say they all are, although I cannot eliminate [the fact] that some are drifting away from auction law. In that case we must carry out in-vestigations,'' he says.

The Auction Law of the People's Republic of China was enacted a mere eight years ago. In Article 61 it stip-ulates: "Where an auctioneer and client declare, prior to the auction sale, that they cannot guarantee the genuineness or quality of an object of auction, they shall not be liable.''

Articles 18 and 27 demand that a seller make clear any defects and the source of origin of an article to the auctioneer, and that the auctioneer must inform potential buyers.

But even Guardian specifies it undertakes no guarantee for the authenticity of a lot in its terms and conditions, and strongly advises bidders to make a personal inspection at preview.

A hard and fast solution might be to amend the law to force auction houses to guarantee their wares but there is resistance.

``We're not selling Oolong tea,'' says Guardian's Kou. ``There's no scientific test to prove conclusively that a piece is real. The quality of work by any artist will vary according to his age, health or even mood.

``Who's to say what is real and what's false? You? Me?''

Scientific tests can make a big difference, especially for older pieces. But by and large Kou is right.

In many cases, even top authorities will disagree over the authenticity of a piece. Artists themselves may have a motive to lie.

Kou also points out that the Chinese industry has not yet established a system for provenance and that is something which obviously takes time to build up.

So what's the way forward? One measure might be to encourage competition from foreign players in the Chinese market. In theory, at least, the international heavyweights of the auction world have been allowed to do business in the mainland since last December - in line with China's WTO obligations.

In Hong Kong, for instance, Christie's now gives a five-year warranty for the genuineness of Chinese artworks and ceramics. Yet despite this change, the big houses have no plans to rush in to China, not least because government restrictions on the export of historical relics discourage overseas collectors.

Another way might be to improve consumer awareness in China and to foster a culture under which people feel they have a right to return faulty products.

More zealous reporting by the media would encourage due diligence by auction houses when vetting pieces, making commercial success more dependent on a reputation for probity.

The same would go for better self-regulation and improved professional ethics. More energetic policing by guilds such as the CAA could sideline negligent auctioneers and those who act in bad faith.

Yet professional associations and their codes of conduct take a long time to develop and China's auction industry is barely a decade old.

This is also true of the expertise that eventually should enable the best houses to weed out dud pieces before preview, or even to give a warranty like Christie's.

In short, mainland auctions will come with a very big caveat emptor until institutions have been developed and experience accumulated.

Back at the 2005 Guardian Spring Auction preview, a punter who identifies himself as Wang Song - a leather trader from Guangzhou - holds up a small torch to scrutinize one of two red ink seal imprints on a picture he intends to bid for - a landscape by the mid-20th century artist Dong Shouping.

``The chops on a picture are one way to tell a fake,'' he says. ``The other two ways I rely on are attention to calligraphy and the style with which the artist uses his brush.''

Song, who has built up a collection of more than 30 paintings from auctions in the capital, says the best way for other amateurs to avoid being duped is to concentrate on the work of just two or three artists.

He is satisfied that all 12 pictures he has inspected today are authentic. But he can't say anything about the other items on show.

``If 90-95 percent of the pieces here are genuine, I call that exceptional,'' he says.

``The only thing you've got to go on is your own judgment.''