DOCTORS are looking into the mystery of a Florida man who awoke speaking only Swedish, with no memory of his past, after he was found unconscious four months ago at a Southern California motel.

Michael Boatwright, 61, woke up with amnesia, calling himself Johan Ek, The Desert Sunrepors.

Mr Boatwright was found unconscious in a Motel 6 room in Palm Springs, California, in February. After police arrived, he was transported to the Desert Regional Medical Centre in Palm Springs where he woke up.

Hospital officials said Mr Boatwright may have been in town for a tennis tournament in the Coachella Valley. He was found with a duffel bag of exercise clothes, a backpack and tennis rackets. He also carried four forms of identification - a passport, a California identification card, a veteran's medical card and a Social Security card - all of which identified him as Michael Thomas Boatwright.

Palm Springs police have documented his information in case anyone lists Mr Boatwright as missing or wanted, authorities said.

In March, doctors diagnosed Mr Boatwright with Transient Global Amnesia, a condition triggered by physical or emotional trauma that can last for several months.

The rare mental disorder is characterised by memory loss, "sudden and unplanned travel," and possible adoption of a new identity, according to the Sun.

After an extensive search, medical personnel and social workers have been unable to locate Mr Boatwright's next of kin. Authorities are still unsure of his birthplace, listed on his ID as Florida - photos show him in Sweden at a young age.

Mr Boatwright doesn't recall how to exchange money, take public transportation, or seek temporary housing like homeless shelters or hotels, the social worker assigned to his case, Lisa Hunt-Vasquez, told the Sun.

He doesn't remember his son and two ex-wives, either.

He has no income or insurance, further complicating his treatment at Desert Regional. And he has little money he can access - only $US180. He also has a few Chinese bank accounts, but can only access one account, which holds $US7, according to the newspaper.

Doctors don't know how much longer he will be able to stay at the centre - aside from his amnesia, Mr Boatwright is in good health. The hospital is currently looking for alternatives that would keep him off the streets. For now, Mr Boatwright is unsure of both his past and his future.

"Sometimes it makes me really sad and sometimes it just makes me furious about the whole situation and the fact that I don't know anybody, I don't recognise anybody," Mr Boatwright told the newspaper.

Last year, a North Dakota college student who went missing for nearly a week before turning up in Arizona said she had a bout of amnesia and didn't know who she was.

Amber Glatt, a 22-year-old Valley City State University student, vanished on the Fourth of July, prompting aerial searches. She contacted her mother five days later from the Grand Canyon. Her mother said Ms Glatt has had recurring amnesia since suffering a head injury years ago.

Ms Glatt told WDAY-TV that after she lost her memory she met a man in a bar who let her tag along on his trip to the Grand Canyon. She said the man eventually saw online that she'd been reported missing and alerted her.

Ms Glatt regained most of her memory.