New childhood photos of North Korean leader Kim Jong-il's third son became public on Tuesday, as chances of the mysterious young man inheriting the communist state with nuclear ambitions heightened after a string of parliamentary promotions earlier this week, Yonhap News reported.

The photos of Kim Jong-un, believed to be now in his late 20s, include one where he is standing among children posing for a group shot against what looks to be a schoolyard.

Kim purportedly spent much of his childhood studying in Berne, Switzerland. One of the photos showed a grinning Kim with his arms around who appeared to his classmate.

The photos, obtained by Yonhap News Agency, are the latest findings in the search for details on the mysterious young man, who outside officials and experts say is being groomed for leadership.

The possibility of him taking over the North in case his ailing father is incapacitated increased on Monday when his uncle was promoted as a vice chairman of the National Defense Commission (NDC), the highest seat of power, during a rare parliamentary session.

The commission led by 68-year-old Kim Jong-il commands absolute power in the country that has been developing nuclear arms while refusing to return to six-nation talks on denuclearization.