IMMIGRATION officials are investigating the case of a man who claims he is an American and has been living on Phuket without a passport for six years.

Police in Patong said that when approached while acting suspiciously at a popular beachfront resort, the man gave his name as Dean Mancuso, aged 50.

The fine for visitors who overstay a visa in Thailand is 500 baht a day. A six-year overstay would amount to 1,095,000 baht.

However, when the man appeared in court yesterday, he was fined 7000 baht and a judge ordered his expulsion from Thailand. Checks are now being made with the US Embassy to confirm the man is who he says he is, and a US citizen.

Once his identity is confirmed, the man is likely to be on a flight out - provided the fare and the fine have been paid. The alternative would be jail, with the fine being lowered at the rate of 200 baht a day.

The unusual circumstances of the case of ''Mr Mancuso'' became apparent after police were called to the Holiday Inn Resort on Patong's beach road on Wednesday.

Staff at the resort told police that an expat was behaving suspiciously. On being approached, the man was not able to produce identification.

He told police his name was Dean Mancuso, and said he had been living on Phuket since 2002.

He said he had lost his passport in the tsunami that struck Phuket and the Andaman coast, killing 5400 people in Thailand, on December 26, 2004.

How Mr Mancuso has survived living on Phuket without a passport has yet to become clear.

More than one Patong resort has reported a man loitering who answers Mr Mancuso's description.

Arresting officer Lieutenant Teerasuk Deensand told Phuketwan today that he was called to the Holiday Inn by a receptionist on Wednesday evening.

''A man had posed as a tourist and possibly a resident,'' Lieutenant Teerasuk said. ''He walked to a room, knocked on a door, then asked the guests inside to give him some money.''

Other resorts had said a man answering Mr Mancuso's description would go into rooms where the door was open and remove items from the minibar.

''Some resorts do not follow up on these kinds of cases,'' he said. ''The only charge against this man is not producing a passport, and being an overstayer.''

One informed source in Patong told of a case that came to light two years ago on Phuket of an American who had overstayed for 12-and-a-half years.

''We helped him pay the fine of 20,000 baht and he died soon after returning to the US,'' the source said. Thai Immigration officers were extremely accommodating and helpful in that case, the source said.

''Phuket was a much looser place once, people could come here and stay and not feel as though they would ever be exposed.

''Times have changed. Phuket is now a tougher place to be on the lam. It's probably a good thing, too.''