SARAJEVO (AFP) -- The nephew of North Korean leader Kim Jong-Un, whose family lives in virtual exile, has graduated from an international high school in the southern Bosnian town of Mostar, a school official said Tuesday.

Kim Han-Sol, who called his uncle a "dictator" in an interview that aired on Finnish TV in 2012, is the son of the North Korean leader's half-brother Kim Jong-Nam, who fell out of favour with his father Kim Jong-Il following a botched 2001 attempt to enter Japan with a fake passport, reportedly to visit Tokyo Disneyland.

"Kim Han-Sol is among 71 student from 28 countries who have obtained a diploma," said the official at the Bosnian school, part of the United World Colleges (UWC) network of international schools.

"He left our boarding school on Thursday, a day after diplomas were delivered. We cannot talk about his grades, but he has completed high school with success," the official, who asked not to be named, told AFP.

Kim, 18, is the grandson of Kim Jong-Il, the late North Korean strongman, who took over from his father, Kim Il-Sung, after his death in 1994 and ruled until his own death in 2011, when Kim Jong-Un took charge of the hermit state.

Kim's family has mainly lived in Macau, southern China, since leaving North Korea.

When Kim arrived in Mostar in 2011, the school claimed that he would not enjoy any special privileges and had passed "all regular selection procedures".

During his two years of study, the school has largely protected him from the media, but in October 2012 he gave an interview to former United Nations under-secretary general Elisabeth Rehn in which he spoke of his desire to make things better" for the Korean people.

Sporting wide, black-framed glasses, two studs in his left ear and a fashionable haircut, he also talked of his hopes for the Korean peninsula's reunification.

Born in Pyongyang in 1995, Kim described a lonely early childhood, spent mostly with his mother's family -- isolated from the grandfather leader he never met.

"I always wanted to meet him, because I just wanted to know what kind of person he is," he said.

The UWC is a network of schools and colleges around the world that aims to promote international and intercultural understanding.