Mr Kim Jong Nam, 41, had been living a life of luxury in the former Portuguese enclave, but disappeared in January after celebrating the arrival of the New Year with his family, according to the Daily Telegraph.
South Korean sources told the Chosun Ilbo newspaper that Mr Kim Jong Nam fled Macau in fear of his life after his younger half-brother, Kim Jong Un, took over as head of North Korea. The father of the two men, Kim Jong Il, died in December last year.
Mr Kim Jong Nam had been groomed by his father to take over the leadership of North Korea until an error of judgment saw him fall from grace.
Arrested in Tokyo in 2001 as he tried to enter Japan on a fake Dominican Republic passport, accompanied by a woman and a child, Mr Kim Jong Nam told the Japanese authorities that he had wanted to visit Tokyo Disneyland.
His father exiled Mr Kim Jong Nam to Macau and the dynasty was left in the hands of his 29-year-old half-brother.
Interviewed by Japanese journalist Yoji Gomi for a book that was released in January, Mr Kim Jong Nam said North Korea is being run by an inexperienced young man who is likely to be acting at the behest of other forces, and that without economic reforms similar to those carried out in China, he could fall from power.
In the book, “My Father, Kim Jong Il, and I: Kim Jong Nam’s Exclusive Confession,” he also voiced strong opposition to the hereditary transfer of power to his half-brother – and claims his father had been equally against the idea until shortly before his death as it runs completely counter to socialist philosophy.
Mr Kim Jong Nam also said he was a strong advocate of a “people-first” policy, instead of the North’s present “military-first” ideal.
In October, South Korean authorities indicted a North Korean agent for violating the National Security Law. Prosecutors said Mr Kim Yong Su had been ordered by the North Korean regime to travel to China in July 2010 to kidnap Mr Kim Jong Nam.
Mr Kim Yong Su has reportedly confessed to planning to bribe a Chinese taxi driver to drive into Mr Kim Jong Nam and disguise it as an accident and claim diplomatic immunity to get him back to North Korea.
Mr Kim Yong Su, who was arrested on a subsequent mission to Seoul, has admitted that the outright assassination of Mr Kim Jong Nam would have been too blatant an act for the rest of the world to dismiss.
The Chosun Ilbo reported that Mr Kim Jong Nam moved to Singapore because his apartments in Macau were known to the media and North Korean agents. He opted to settle in Singapore as it is easy for him to travel to Europe, where his 17-year-old son is a student at an international college in Bosnia. His wife, Lee Hye Kyong and his daughter, 13, are believed to still be living in Macau. AGENCIES