A photograph of a plump, poker-faced young man seated near North Korea's ailing ruler confirmed the rise of Kim Jong-il's youngest son as the leader-in-waiting of the secretive state.
Kim Jong-un was this week appointed to senior political and military posts in the isolated state, whose aspirations to be a nuclear weapons power has worried the outside world for years.
The photo, published by state media today, is the first picture since the appointment of the 20-something third son of Kim Jong-il and about whom little is known other than he was educated in Switzerland. The only previous known photos of him date back to his childhood.
Park Young-ho of the Korean Institute for National Unification said the photograph provided unwritten confirmation that the young Kim was the heir apparent.
"It has now been made public he is the successor ... the picture shows that Kim Jong-un is now the second man in North Korea's power echelon," he said.
The official group photograph of dozens of military and civilian officials showed a young man seated in the front row, two places to the right of Kim Jong-il.
Although he was not officially identified, the young man was the only person in the photograph around Jong-un's age. A unification ministry source in Seoul said the man, dressed in traditional Maoist-style attire, was most likely Kim Jong-un.
Seated immediately to the leader's right was another rising star, Ri Yong-ho, who is considered among the new generation of military cadre who could act as a link when Kim turns over power to his son.
The photo was taken in front of the Kumsusan Memorial Palace, the former official residence of Jong-un's grandfather and founder of the North Korean state Kim Il-sung - and to whom he showed a resemblance.
A few hours later, North Korean TV showed footage of the same sombre-looking young man at the ruling party conference, standing amongst hundreds of other delegates in an austere auditorium.
The young Kim, with short hair and of average height, was pictured clapping in the first row of the audience, and was positioned near his aunt and "minder" Kim Kyong-hui.
After months of speculation, the untested Jong-un was this week made second-in-command to his father on the ruling Workers' Party's powerful Central Military Commission.
Jong-un, whose existence was not acknowledged in North Korea until this week, was made a general in one of the world's largest armies. He was also appointed a party Central Committee member at the biggest political meeting in the impoverished state for 30 years.
Rising with him were the leader's sister Kyong-hui and her husband, creating a powerful triumvirate ready to take over the family dynasty that has ruled North Korea since its founding after World War Two.
Kim Jong-il, 68, is believed to have suffered a stroke in 2008 although it was difficult to assess his health from the latest photo. North Korea's paramount leader has shown no sign of losing his grip on power and was reappointed on Tuesday as secretary-general of the Workers' Party.
A stable succession would be a relief to its economically powerful neighbours - China, South Korea and Japan - who worry regime collapse could result in massive refugee flows and possibly descend into civil war.
Meanwhile, the first meeting between the militaries of the rival Koreas in two years ended without progress today, officials said.
During the talks at the border truce village of Panmunjom, South Korean military officials "strongly urged North Korea to admit to, apologise for and punish those responsible for the attack on the Cheonan warship", the defence ministry said.
Ties between the Koreas, technically still at war after agreeing only a truce at the end of the 1950-53 Korean War, plummeted to the lowest level in decades with the sinking of a South Korean warship in March, killing 46 sailors.
South Korea says a North Korean submarine fired a missile that sank the boat, but Pyongyang denies responsibility.