A man detained by immigration officials at Narita airport on suspicion of trying to enter Japan illegally has admitted he is the oldest son of North Korean leader Kim Jong Il, Japanese public security officials said Thursday.

A copy of the forged Dominican Republic passport used by a man thought to be the son of North Korean leader Kim Jong Il was released by immigration officials.

The officials quoted the man, who confirmed that he is Kim Jong Nam, as saying he wanted to visit Tokyo Disneyland.

Immigration officials said Kim arrived at the airport, east of Tokyo in Chiba Prefecture, around 3 p.m. Tuesday on a Japan Airlines flight from Singapore, adding that he was traveling on a forged Dominican Republic passport under the name Pang Xiong. Japan has no diplomatic ties with North Korea.

He was detained along with two women and a 4-year-old boy, the officials said.

The man's facial features "resembled closely" those of the younger Kim, sources close to police said. The date of birth on the passport was May 10, 1971, the same as Kim's, they said.

Justice Ministry sources said the government plans to deport him to China in the next few days.

South Korean sources in Japan said it was "highly likely" that the detained man was Kim, adding that Kim has entered Japan before on a fake passport.

The General Association of Korean Residents in Japan (Chongryun), which represents North Koreans here, said it learned of the news through media reports, but that it had no information on the matter.