Caught at a Clapton concert: the secretive son who would be the next Dear Leader

He looked like any other young man enjoying a rock concert in Germany. He was wearing a black leather jacket over jeans and a T-shirt, had a young woman in tow, and a digital camera to record the experience.

Only the pudding basin haircut provided a clue that this was no ordinary young Asian influenced by Western fashion trends. The fan who was photographed enjoying an Eric Clapton concert earlier this month has been identified as the second son and heir apparent of the reclusive North Korean leader, Kim Jong Il.

At least Kim Jong Chol, 25, wasn't sporting his father's trademark bouffant hairdo as he joined the caravan of Clapton followers who watched the guitarist perform in four cities: Frankfurt, Stuttgart, Leipzig and Berlin. The rare sighting of a family member of the "Dear Leader" is such an event that Japanese television broadcast the images of Kim Jong Chol and his entourage of five. In addition to the young woman who was accompanying him, he was shadowed by bodyguards, a maid and a tour guide.

However, as with most of North Korea's affairs, the facts are scarce: Kim Jong Chol was born of a liaison between the North Korean leader and Ko Young Hee, a dancer, who became the North Korean leader's consort. Before her death in August 2004 at the age of 51, Ko Young Hee was rumoured to have had Kim Jong Il promise her that one of her two sons would be named as the heir apparent amid a vicious power struggle within the ruling family.

Intelligence sources suggest that Kim Jong Chol is fluent in English and German, having attended an international school in Switzerland in the 1990s - it was two American former classmates who recognised him from the concert video footage. He returned to North Korea in 2000, but recent reports suggest he has registered as an employee of the North Korean liaison office of Unesco in Paris under an alias, to ease his movements around Europe.

In the absence of verifiable facts, there are rumours, claims and counter-claims. They are reminiscent of the allegations, originated by the South Korean and US secret service, which questioned Kim Jong Il's mental state before he succeeded his father Kim Il Sung, the country's founder and "Great Leader".

One of the most extreme rumours is that Kim Jong Chol suffers from an excess of female hormones. That particular claim originated from Kenji Fujimoto, who worked as Kim Jong Il's sushi chef for more than a decade and who, in a book about his experiences, quoted the North Korean leader as dismissing his second son as potential heir for being effeminate. However, Kim Jong Chol's fortunes seemed to rise in 2001 when his elder half-brother, Kim Jong Nam, was caught at a Japanese airport trying to enter the country on a false passport. The incident reportedly incurred his father's wrath. A year later Kim Jong Chol was being touted as a potential future leader with reports that the North Korean military had launched a campaign of glorification of his mother, hailing her as "the respected mother". A similar process took place when Kim Jong Il was designated as the successor to his father.

But analysts are deeply sceptical about whether North Korea's Communist dynasty can survive through to a third generation. They point out that Kim Jong Il does not command the same level of devotion as his father and that when he took over from Kim Il Sung in 1994, the economy was nowhere near as decrepit as it has become. They also say that Kim Jong Chol is almost as much an unknown quantity at home as abroad.