Man cannot remember anything of past life after being found unconscious in Palm Springs motel room

Doctors are looking into the mystery of an American man who awoke speaking only Swedish, with no memory of his past, after he was found unconscious four months ago at a motel in southern California.

Michael Boatwright, 61, woke up with amnesia, calling himself Johan Ek, the Desert Sun reported.

Boatwright was found unconscious in a motel room in Palm Springs in February. After police arrived, he was transported to the Desert Regional medical centre.

Hospital officials believe 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 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 Boatwright as missing or wanted, authorities said.

In March, doctors diagnosed 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.

Medical personnel and social workers have been unable to locate Boatwright's next of kin. Authorities are still unsure of his birthplace, listed on his identification as Florida, while photos show him in Sweden at a young age.

Swedish public records show Boatwright lived there on and off between 1981 and 2003. Several Swedes on Tuesday said they knew of him as an American with an interest in medieval history and jousting.

Olof Sahlin said he met Boatwright in about 1985 through their joint interest in medieval history. He said he saw him at jousting events in the 1980s and early 1990s.

"He was nice, sympathetic and talented at fighting in plate armour," Sahlin told Associated Press. "A little bit reserved maybe."

Sahlin said he never knew how Boatwright made a living during his time in Sweden but has heard from other friends that he briefly worked as a personal assistant and in the construction sector.

Sahlin said their last contact was in 1999 and he didn't know what happened to him after that.

Boatwright does not remember his son and two ex-wives. He also does not know how to exchange money, use public transport or seek temporary housing such as homeless shelters or hotels, the social worker assigned to his case, Lisa Hunt-Vasquez, told the Sun.

He has no income or insurance, further complicating his treatment at Desert Regional. And he has little money he can access – only $180 (£120). He has a few Chinese bank accounts but can only access one account, which holds $7, according to the newspaper.

Doctors do not know how much longer Boatwright will be able to stay at the centre. Aside from his amnesia, Boatwright is in good health and the hospital is looking for alternatives that would keep him off the streets. For now, 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," Boatwright told the newspaper.