The Post report said that while Kim had been living in and out of top hotels in the former Portuguese enclave, his wife and children had been based in a luxury villa on the island of Coloane.
"He's been on the move for much of the decade, but Macau is the place he calls home now," a source told the newspaper.
"He's been free to stay as long as he lives quietly. He believes he is among friends and he appears to be happy."
|Little is know about Kim |
Jong-il's family [AP]
The investigation also found him making regular visits to Hong Kong but was refused entry on his most recent trip amid international condemnation of North Korea’s first nuclear weapons test in October.
He travelled on Dominican Republic and Portuguese passports, while his latest trip took him to Beijing for a health check-up, the report said.
In 2001, Kim was caught entering Japan on a Dominican Republic passport and was deported to China. At the time he reportedly told officials he was taking his family to Tokyo Disneyland.
North Korea is one of the most impoverished and reclusive countries in the world and has relied on international aid for much of the past decade to feed many of its 23 million people.
Japan the US and several Western countries accuse Kim Jong-il of starving his people to fund North Korea's armed forces and the development of nuclear weapons.
Macau's long links with North Korea have come under scrutiny since one of its banks, Banco Delta Asia, was accused by the US government of laundering proceeds from Noerth Korean counterfeit operations.
Some $24 million of the bank's assets were frozen in late 2004 and its management placed under the control of the Macau government following the allegations by the US Treasury.
Reports at the time also linked the cash funnelled through Macau to North Korea's nuclear programme.
"Macau has been trying hard to finally play its part ... the fact that the young Mr Kim has been using the place as his base puts them in a very difficult position," a Western diplomatic source was quoted as saying.