When, in 2001, the magazine Asiaweek named Li Hongzhi, founder of the Falun Gong spiritual movement, "the most powerful communicator in Asia", Chinese embassies and consulates around the globe went into paroxysms. They had devoted much of their energy in previous years to vilifying the name of Li, whom the Chinese government described as a swindler, a conman and an accessory to murder. Both sides in the argument between Li Hongzhi and the Chinese government make extravagant and unverifiable claims. But whatever the truth, the reality is that Li is a man who came from nowhere to found first a national then a worldwide movement and that, despite the unrelenting repression of the government, his movement persists.

Whatever the merits of his philosophy, then, it is worth asking who he is and why he has had such success. The trouble is that most of the details of his life are disputed - even his birth date. The official date of Li's birth is 7 July 1952. Li, however, prefers 13 May 1951 - a date that coincides with the birthday of Sakyamuni, the historical Buddha. Asked to explain, he claimed that the original date had been misrecorded and the change was an innocent correction. "I have never said I am Sakyamuni," he said in one interview. "I am just a very ordinary man."

His childhood was spent in Jilin Province, north-eastern China, where, except for playing the trumpet, he failed to distinguish himself at school. On leaving school, he worked on a People's Liberation Army stud farm and then held a variety of jobs that included trumpeter in a police band, working in a guest house, security guard and grain store clerk. In later years, Li put out his own version of his biography, one that explained how a man from such an otherwise undistinguished background became the spiritual leader of so many millions. This version has him spending the years between age four and age eight in intense training in qigong - Chinese martial arts - under a Buddhist master, then following up with more training, aged 12, at the hands of a Taoist immortal. By the end of this, his followers believe, Li had mastered such useful skills as being able to pass through solid objects. These he kept under wraps in his subsequent career until, in 1992, he founded the Falun Gong movement.

China at the time was a hotbed of cults and religious groups. The death of Mao Zedong and the retreat from millenarian communism, the disillusionment of the generation that lived through the cultural revolution - all had created a vacuum of belief that was to be filled with everything from Confucianism to a belief in aliens. Li's philosophy inclines to the aliens end of the spectrum but this did not diminish Falun Gong's popularity. Nor did it suffer, in the early years, from government disapproval. After the crackdown in Tiananmen Square in 1989, the Chinese Communist Party had concluded that western ideas could be dangerous. Casting around for something home-grown, it fell on qigong as a possible source of national renewal. Qigong is the generic term for a range of practices that seek to cultivate the spiritual and physical energy the Chinese call qi. Once nurtured through meditation and breathing exercises, qi can be directed around the body - to cure illness or simply to perform fairground tricks: at the time, qigong practitioners could be seen in every Chinese high street, lifting weights or performing other feats of strength for money.

For the government, the army and many prominent Chinese scientists, qigong was to be encouraged as an indigenous and politically safe source of national pride. Or so they thought. Li Hongzhi appears to have started to practise qigong in 1988; he founded Falun Gong, also known as Falun Dafa, just four years later. It appealed for several reasons. It preaches righteousness in a country where corruption is rampant. It promises good health in a country where millions had lost access to medical services. It appears to give a sense of purpose and well-being to its adherents, many of whom have chosen to die rather than renounce it.

Falun Gong spread rapidly and when Li published his book Zhuan Falun, in 1993, it became a bestseller. He was admitted to the official qigong organisations and invited to lecture to the army. Perhaps it was the pace of Falun Gong's expansion that first caused alarm: Li claimed 100 million followers in China at one point, many more than the Communist Party could claim as its membership. Or perhaps it was the suspicion that Li had another agenda. In any event, a dispute arose in Tianjin following the publication there of an attack on Li. His followers protested but failed to win satisfaction. They then did the traditional Chinese thing: they petitioned the emperor - or the emperor's heirs, the leadership of the Communist Party.

In an amazing coup de theatre, 10,000 of Li's followers silently surrounded Zhongnanhai, the communist leadership compound, in a peaceful demonstration in 1999. For the party, the terrifying thing was that it had not known this was coming - or who these people were. The party suspected a conspiracy. From that point on, it was war.

Li, by this time, had left the country. In 1998 he fled to the United States and New York, where he now lives with his wife and daughter. He seldom gives interviews. The following year, while on a visit to Australia, he claimed he was free to move in and out of China as he pleased. But for the Chinese government, he remains high on the most wanted list. His devotees have been systematically persecuted in China but the movement persists and internationally he still has a substantial following. His followers claim that there is no Falun Gong organisation as such, but this is belied by their evident skills in organisation and propaganda. In China itself, they have learnt from the early history of the Communist Party and function as an effective clandestine network. When Falun Gong practitioners break cover in China, they continue to be arrested and treated brutally. Hundreds have died in prison.

As for Master Li, his message is available in a torrent of video- and audiotapes, websites and books. He continues to preach that there are aliens on earth, that he is a being from a higher level and that his followers can develop X-ray vision. Falun Gong, he says, is not a religion - and indeed, it lacks the rituals that conventional religions feel required to provide. Yet, however it is defined, it remains an extraordinary phenomenon.

Li Hongzhi Born 1952 in Gongzhuling City, China. Leader of Chinese spiritual sect Falun Gong, which he founded in 1992. China outlawed the sect in 1999 and has persecuted many of its millions of members. Author of Falun Gong (1993) and Zhuan Falun (1995; Turning the Law Wheel). Currently lives in New York