TOKYO (AFP) - The older brother of Kim Jong-Un has reportedly told a Japanese newspaper that he believes North Korea's new leader is likely to be merely a symbol used by ruling elites to maintain their grip on power.

The Tokyo Shimbun, which has interviewed Kim Jong-Nam in the past, said Thursday it had received an email from the exiled son of the secretive state's late strongman in which he opposed the notion of inherited power.

"Anyone with normal thinking would find it difficult to tolerate three generations of hereditary succession," said the email, which the paper said was sent on January 3.

"I question how a young heir with two years (of training as a successor) would be able to inherit... absolute power," he said, according to the paper's Japanese translation of the message.

"It is likely that the existing power elites will succeed my father by keeping the young successor as a symbol."

The article was bylined Yoji Gomi, who next week publishes a book based on his extensive interviews with Kim Jong-Nam and e-mail exchanges between them.

Kyodo news agency has previously reported that Gomi became acquainted with Kim Jong-Nam after the pair met in Beijing in 2004.

The reporter interviewed Kim in Macao and Beijing last year for a total of around seven hours, the agency said.

Jong-Un was propelled to power by the death of his father, Kim Jong-Il, which was announced on December 19.

His half-brother Jong-Nam has lived in virtual exile, mainly in the Chinese territory of Macau, for many years after falling out of favour with his father, who in turn inherited the rule of the impoverished country from his own father.

Two years ago and with his health rapidly deteriorating, Kim Jong-Il moved Jong-Un -- believed to be in his late 20s -- into the position of designated successor, giving him military posts and raising his profile.

Jong-Nam last year gave an interview to the Tokyo Shimbun in which he said he opposed the idea of a power transfer within North Korea's first family.

"Hereditary succession did not happen even under Chinese Chairman Mao Zedong," he said at the time. "(Hereditary succession) does not fit socialism and my father was against it."

Tokyo Shimbun said Jong-Nam did not directly respond to questions over whether he attended the elaborate funeral and memorial ceremony for his father in North Korea.

Earlier this month, Japan's Yomiuri Shimbun newspaper reported Jong-Nam secretly visited Pyongyang after learning about his father's death, and before it was publicly announced two days later.