A Japanese newspaper says that two of North Korean leader Kim Jong-il's sons, one of which is his reported heir apparent, recently visited China.

The Asahi Shimbun said Thursday that the North Korean leader's third son and heir apparent, Jong-un, recently made a secret visit to Beijing, where he met with Chinese President Hu Jintao.

The daily said Kim Jong-il’s eldest son, Jong-nam, flew into Bejing from Macau while Jong-un was visiting China.

Quoting North Korean officials, Asahi said Jong-un introduced himself to the Chinese president as the successor of the North Korean leader.

Jong-un reportedly returned home on Wednesday after visiting Guangzhou, Shanghai and Dalian.

The Chinese Foreign Ministry denied Asahi's Tuesday report on Jong-un’s visit to China. North Korea's embassy in Beijing also denied the Japanese report, accusing the Japanese media of fabricating information.

According to the Japanese newspaper, Beijing might have found it burdensome to confirm its contact with Pyongyang at a time when the U.N. is considering imposing new sanctions on the North for its latest nuclear test.