PALM SPRINGS, Calif. – 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 Sun reported. Boatwright was found unconscious in a Motel 6 room in Palm Springs in February. After police arrived, he was transported to the Desert Regional Medical Center where he woke up.

Hospital officials said 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.

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 characterized by memory loss, “sudden and unplanned travel” and possible adoption of a new identity, according to the Sun. The Sun reported it had found Boatwright’s sister in Louisiana but she was unable to shed any light on what had happened.

“I haven’t talked to him in years. He just disappeared,” Michelle Brewer said Monday.

Brewer estimated she had last spoken to her brother about 10 years ago.

“He’s always been just a wanderer,” Brewer said. “Then he’d come back when he needed some money or something from somebody. Then he’d take off again.”

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

Swede Olof Sahlin said he met Boatwright around 1985 through their joint interest in medieval history. He said he saw the American at jousting events regularly in the 1980s and sporadically in the early 1990s.

“He was nice, sympathetic and talented at fighting in plate armor,” Sahlin said. “A little bit reserved maybe.”