When her lovers ended up in court for corruption, the Queen of Mistresses coolly testified against them. She sat out four years in detention before being released this year with most of her wealth intact, to begin a new, but very discreet, life in Hong Kong.

Her story casts a damning light on the rampant corruption that drives modern China and, with her lovers convicted in closed trials, might have remained a dirty little secret if details hadn't leaked out and caught the attention of respected Beijing magazine Caijing. The magazine was able to identify high-profile lovers and hinted that the diaries she kept throughout her astonishing rise and fall may contain the names of even more important people.

The account of how a mistress turned the tables on her powerful lovers by exploiting their lust and greed has gripped people across the mainland, where, for centuries, concubines have been accepted and kept in their place. It has inspired both outrage and admiration, and the issue of the magazine it appeared in disappeared from shop shelves as quickly as officials could scurry around to put a lid on the embarrassing saga.

They were too slow, though. Her story was circulated on the internet by citizens revelling in the schadenfreude of seeing corrupt officials brought low by a woman who started out with no money, no privilege and no power - just razor-sharp wits.

Newspapers did not report openly on the case but popular Beijing-based blogger Xi Bu crowed: 'In a nation where women's dignity is trampled on with abandon, Li Wei has made use of her charm in a miraculous way. She should be respected as a wonder woman.' More revelations would surely follow, he predicted, if the country's most famous kept woman chose to reveal more details of her affairs. 'Li's diary is like a sword of Damocles hanging over China's corrupt officials,' he said.

It was on the immaculately manicured lawns of the seaside mansion she bought in Qingdao that Li - a woman known more for her sexual charisma and a penchant for tight-fitting clothes than for her beauty - finessed her financial mastery. Here, in one of the most exclusive corners of China, Li hosted summer parties at which servants shuttled around Renaissance-style fountains to serve drinks to visiting business leaders and officials.

'The parties were famous and talked about all over Qingdao,' recalls a local government official, who asks not to be named. 'Some of the most senior party officials in the country were said to go there and the entertainment was extravagant.'

Lines of black cars would travel from Qingdao airport to the tree-lined streets of the city's exclusive Eight Great Passes district, where Li sat resplendent in her palace, ready to entertain the powerful and to exploit her high-ranking connections. According to Caijing, fine wine flowed. Political connections were forged. Obscene sums of money changed hands in plain envelopes. Multimillion-dollar deals were agreed. Flirtations were initiated and future lovers seduced.

The heady scenario could hardly be further removed from Li's humble background. Born in war-torn 1960s Vietnam, she fled as a refugee with her parents at the age of seven and settled in Yunnan province. In this corner of the country, far from the seats of power, she began her career trading in tobacco and slowly built a network of business and political connections.

One of her early lovers was Zheng Shaodong, a married Ministry of Public Security official who helped Li and her sisters get residency papers and fake IDs so they could travel freely between Hong Kong and the mainland, to build up her business. That shrewd move paid rich dividends as her business flourished.

In the 90s, she married a local government official working in the tobacco bureau, who introduced her to Li Jiating, governor of Yunnan province and 20 years her senior. According to Caijing, one eye-opening encounter made Li realise the potential power of being a mistress: at a party, she saw the governor give his previous mistress a pleasure boat worth six million yuan. Soon afterwards, he dumped his mistress and took Li as a lover instead.

It was with the governor that Li first turned power into profit, helping him get residency for his son in Hong Kong in return for tobacco export quotas and exploiting business contacts to bring in handsome bribes and backhanders. It was a dangerous liaison that nearly ended in disaster. In 2001, Li Jiating was convicted and jailed for taking millions of yuan in bribes. Li Wei was arrested and questioned, but released. How she escaped prosecution is uncertain but the pattern repeated itself in years to come: she displayed no loyalty to her lovers and would cheerfully take the lion's share of profits from corruption while leaving the men to pay the price.

Li Wei's close shave with the law taught her an important lesson that she later passed on in conversation with friends when justifying her multiple lovers.

'You can't afford to invest everything in one person,' she would say. 'You need a huge relationship net, like an umbrella.'

By now moving effortlessly in senior party circles, Li snared her most important lover of all in Du Shicheng, the extremely well-connected Communist Party secretary of Qingdao and the man whose patronage would propel her into the ranks of the super-rich. Du - notorious for his quick temper and arrogance - quickly fell under her spell and agreed to help her secure huge tracts of real estate for rock-bottom prices in a city that had some of the most sought-after property in the country.

These were golden years for Qingdao. The national economy was booming and the city, with its seaside setting within easy reach of both Shanghai and Beijing, was a popular holiday destination. What's more, it was soon to host the water sports events in the 2008 Olympics. That meant billions of yuan in government money was being made available to renovate and upgrade the city as China set out to stage the most extravagant and expensive games in Olympic history.

An official who worked in the Qingdao government during Du's time there says: 'Du was completely in awe of Li and would have done anything she asked him to. He was very vain and self-possessed but not terribly bright. He let her do the thinking.'

With Du at her bidding, Li quickly became the most powerful player in Qingdao's property market - setting up home in a mansion at 1 Shanhaiguan Road, which she got for a fraction of its value, and winning contracts to develop prime seafront locations. Those contracts, many awarded without them having gone through a bidding process, included the rights for much of the development at Qingdao's Olympic water-sports area, which transformed a former shipyard into a luxury marina and shopping mall modelled on Darling Harbour in Sydney, Australia.

Du signed over the rights to the land to Li's burgeoning real-estate firms. In return, according to testimony she would later give at his corruption trial, she would summon him to her home to receive envelopes stuffed with cash. Between 2003 and 2006, she said, she gave Du sums ranging from 200,000 yuan to one million yuan.

'I did it to thank him for the help he gave me with my business activities in Qingdao and because I wanted him to help me again in the future,' she said.

The sums Li handed to Du were trifling compared with the vast profits she could have reaped in the pre-Olympics boom, but her testimony was to seal Du's fate and guarantee his disappearance from public life, and possibly from life in general; this betrayed lover is rumoured to have died in prison, a year after being jailed for corruption. Some accounts say he committed suicide, others that he was murdered to stop him naming more senior officials he did business with. Whatever the truth, he has not been seen or heard from since being imprisoned.

Despite Du's devotion, Li was all the while nurturing new lovers and new deals. When Du introduced her to a friend, Chen Tonghai, chairman of oil company Sinopec, Li took him as a lover, later receiving petrol-station rights and shares worth tens of millions of yuan.

When Li was arrested for tax evasion, in October 2006, Chen tried to intervene to halt the investigation. She repaid him by testifying against him when he, too, was arrested for corruption. He was sent to Qincheng Prison, with Du.

Li's been linked to other men, including a former deputy head of the Supreme Court, a deputy governor of China Development Bank and a former vice-mayor of Beijing - all of whom have been jailed for corruption, some receiving suspended death penalties. Her willingness to testify against her lovers delighted police officials and may have saved her from prosecution.

'Li Wei kept a diary which recorded in detail her lovers and the deals she did,' a police official involved in the investigation says. 'Her diary was extremely useful in the corruption cases that followed. It showed that behind every successful woman, there are many bad men.'

Li's co-operation with prosecutors resulted in her walking free this year to millions in savings and two companies registered in Hong Kong - one of them a tobacco firm - after her time in detention. She has never formally been charged with any offence other than tax dodging.

As her celebrity spreads, internet forums are abuzz with speculation about just how she managed to seduce so many high-ranking officials.

'There are many women more beautiful than her in China, but none as calculating and intelligent,' one unofficial internet news site notes.

Another site claiming inside knowledge of her case observes: 'Li Wei's great skill was her ability to think and act like a man. She used her femininity to entice her lovers - but in the way she exploited her connections, she behaved like the most cynical of male party officials.'

Whatever her methods, her case has struck a chord with women across the country. Any man caught exploiting his connections to make a fortune would be vilified by the public - but Li did what millions of Chinese women may yearn to do: she outsmarted corrupt men with power. Her case is widely seen as having fed just desserts to lovers who took a mistress behind the back of their wife, following a tradition of wealthy men taking concubines or 'second wives' that stretches back thousands of years. More than 90 per cent of mainland officials investigated for corruption in recent years have kept mistresses.

An ageing Chairman Mao believed sex with young mistresses would keep him alive, and a recent successor, Jiang Zemin, reportedly had a long-term mistress - Song Zuying, a singer 40 years his junior - whose existence was accepted without surprise or any hint of popular outrage. Today, however, there are indications that millions of 'kept women' are becoming increasingly resentful of their position in society and more willing to push their married lovers for a bigger share of their wealth.

The newly formed China's Association for Mistresses has an online forum where the mistresses of wealthy older men exchange tips on how to deal with their lovers and even staged 'mistresses festivals' in mainland cities to mark International Women's Day, on March 8. Referring to male lovers as 'uncle' or 'the old man', its website includes advice on how much money to expect - women should not settle for less than 20,000 yuan a month, one posting advises - and directions on how to extract more.

'He bought me a car which was worth 300,000 yuan and he's promised to buy me a flat on top of my monthly allowance of 20,000 yuan,' says one mistress, calling herself Fei Er, with a lover 22 years her senior. 'He's also given me a credit card with a limit of 500,000 yuan and I've almost hit my limit already. If he wants to keep me and isn't prepared to marry me, he's got to pay for me and he knows that.'

With their status forever precarious and unreliable, the core objective of most mistresses is to make as much as they can from their relationships before the inevitable, final split.

'If I'm dumped I'd rather cry on the back seat of a BMW than a bicycle,' one mistress remarks.

The price of philandering is rising in line with the mainland's soaring economy. The annual cost of keeping a mistress is now estimated at 50,000 yuan and a 2008 survey found that mistresses bought one-third of all luxury goods - mostly on credit cards funded by their lovers, of course.

Even the biggest-spending mistress would admit, however, that Li is in a different league.

'She has shown Chinese men that they can't just always have it their own way,' a university undergraduate with a businessman lover 15 years her senior says. 'She wouldn't have been able to do what she did if her lovers hadn't been corrupt in the first place. They are the ones who abused their power. Li Wei just took advantage of their greed and turned it to her advantage.'

That observation touches on the most uncomfortable truth of Li's case as far as mainland leaders are concerned: if one woman can find so many corrupt officials to take as lovers and exploit, how many must there be on the take?

'Making money is easy in modern China,' says blogger Xi. 'But making money without getting sent to prison for corruption takes real talent, and that's what Li Wei has done.

'Our market economy in China is actually a power economy. Whatever people think of her and the things she did, Li is a heroine of sorts and a morality tale for early 21st-century China.'

Professor Jean-Pierre Cabestan, head of government and international studies at Baptist University, says: 'People are very cynical in today's China. They like people who cheat the authorities because they don't trust officials and they don't like the government.'

He compares the situation to that which prevailed in 19th-century Europe: 'There's a lot of wealth around and people are dumped and betrayed when they are no longer useful.' Although, he points out, it is usually the men who dictate the affairs.

A recently sacked railways minister involved in corruption was rumoured to have had 18 mistresses, Cabestan says. 'Everybody is using someone else.'

During her detention, one asset the government did seize back from Li was her Qingdao mansion, now leased to a state-owned company that uses it to host business guests. The parties are long over, its lawns are overgrown and the fountains are dry.

The legacy of the Queen of Mistresses, who made the mansion her palace and used it to exploit the greed of some of the country's most powerful men, is growing, however, nourished by a stream of sightseers and an increasing number of online commentators, sympathisers and admirers among them.

Mao once said: 'Women hold up half the sky.' The lesson from the Li Wei story is that a clever woman can also bring the sky crashing down on her lovers.