Tokyo:  The eldest son of North Korea's late leader Kim Jong-Il has secretly visited Pyongyang to pay his last respects, a major Japanese newspaper reported on Sunday.

Kim Jong-Nam's absence from a state funeral and other official events related to his father's death has fuelled speculation about a possible power struggle with his half-brother Jong-Un, who has taken over North Korea's top posts.

Jong-Nam, 40, flew to Pyongyang from the Chinese territory of Macau, where he mainly lives, on December 17 after learning about his father's death that day, Yomiuri said. He left after ‘a few days’ and was now in Macau, the report said.

Using a passport under the false identify of Kim Chol, he avoided a flight via Beijing which might have given more exposure to his return home, the newspaper said quoting a source connected to North Korea.

Jong-Un, aged in his late 20s, was presumed to have accompanied his older brother to see their father's body, Yomiuri said.

The eldest son probably refrained from attending the December 28 funeral because he did not want to give rise to possible arguments over ‘why the third should become the successor,’ the source told.

The source added that Jong-Nam "pulled out of the succession race several years ago by himself, saying he had no interest in politics," according to Yomiuri.

Jong-Nam has lived abroad for years after apparently falling out of favour with his father for trying to enter Japan on a false passport in 2001.

Jong-Il eventually backed his youngest son from another marriage to continue the dynasty. The North has proclaimed Jong-Un the 'great successor' and the supreme commander of the military after his father's death due to a heart attack aged 69.

South Korean news agency reported last week that Jong-Nam had been ‘placed under Chinese protection.’

Jong Nam has described as a ‘farce’ South Korean media reports in 2009 that people around Jong-Un had tried to assassinate him in Macau, the source told.