He is about 5 feet 6 inches (1.68 meters), has a slight build, large blue eyes, prominent dark eyebrows and a balding pate with a shock of white hair that gives him the look of a mad professor.

His manners are impeccably English -- polite, deferential and well-spoken, not the posh upper class inflection of the British aristocracy, but standard broadcast speak.

He says he is descended from royalty, but not from the House of Windsor. He insists that he is definitely not British as everyone assumes, but a blue-blooded German. And his name is Karl Frankfurt.

At the time of the 2006 soccer World Cup in Germany, he suddenly found himself at the Mannheim train station without baggage and any form of identification. He had lost his memory and went to the police for help. "I must have had sunstroke," he explained in an interview in his present domicile, a nursing home in the picturesque Odenwald forest near Heidelberg.

The police, who had been on high alert because of the soccer games, were unsure about whether they were being conned and took him to a nearby psychiatric clinic in the small German town of Wiesloch for evaluation.

The case seemed to be genuine and photos of the "mystery man" were released to the press in Germany and Britain. The investigation even went as far as America, but no one could identify him. Nobody had reported him missing either.

My name is "Karl"

The German authorities need a name and date of birth to set up a file, so he told them he was "Karl". He said he was born in Frankfurt, so Frankfurt became his surname. They guessed that Karl was about 60 years old.

No one knows how he wound up at Mannheim train station, and Karl often deflects the question when asked about it, said Ralf Steigleder, resident director of the nursing home. Since October 2006, Karl has lived in Odenwald and is well-liked by the staff and other residents, who communicate with him in English. But if he is German, why doesn't he speak the language?

Karl seems a tad exasperated at the question. He speaks 36 languages, among them several German dialects, but can't get access to all those languages stored somewhere in the recesses of his mind. He says he's lived all over the world and talks about his distinguished pedigree, which not only consists of German dukes and barons, but a French grandmother by the name of Coco Chanel.

Is his artwork a clue to the past?

His detailed drawings, watercolors and collages of sports cars and military aircraft, line the walls of his room, which is immaculately kept. He keeps a diary and his penmanship is elegant, artistic even. He says he designs cars and airplanes. He joined the Luftwaffe as a ten year old and flew the Vickers Vanguard turboprop jet. "I'm not lying, you know. I'll be happy to take a lie detector test," he offers.

Perhaps something very English will jog the memory? Does he enjoy eating Marmite on buttered toast?

"English food is crap. German food -- I love it!" he said.

Steigleder said that Karl lives in his own fantasy world.

"There is no diagnosis for his condition, which is hard to define," he said. "But he is happier than others who are not mentally ill. He is well-adjusted and gets along with others, but tends to keep to himself, maybe because of the language barrier too."

A name and British passport record is found

One thing is clear: Karl likes Germany and German food so much, he wants to stay. But last September when the trail to uncover Karl's official identity went cold, a physician in Scotland said he recognized Karl, who used to be an outpatient at an Edinburgh hospital by the name of Norman Henry McMullan.

The international police force Interpol had matched up some fingerprints and the British passport office pulled up old records confirming that Norman a.k.a. Karl was born in Edinburgh and is indeed British. And now that could change everything.

As European Union citizens, Britons have the automatic right to live in Germany, but not to draw on social welfare entitlements from the German state, according to Karl's legal guardian, Wolfgang Wagner, who has filed an application for incapacity benefits on behalf of Karl under an EU health scheme that is now pending.

Who will now pay for Karl's upkeep?

"Now that we know for sure that Karl is British, we might have a problem," said Wagner, who explained that if the UK Work and Pensions department declines to pay for Karl's upkeep in Germany, he could be sent back to Britain against his will. On the other hand, had Karl remained anonymous, the social services agency in the Rhein-Neckar region, where he lives, would have continued to provide for him indefinitely, added Wagner.

The cost of room and board at the nursing home is 1,500 euros ($2,226) monthly, an amount that does not include healthcare and other incidentals, said Steigleder.

Besides, does knowing about Karl's past bring any benefits at all? Moritz Siebert, a German medical doctor and filmmaker in England, has recently completed a short documentary about Karl.

Siebert, who dug up some official records and questioned neighbors in Karl's childhood home, a working class district in Edinburgh, knows this much about Norman: He was an only child of parents who had died in the 1980s. He had lived with his parents as an adult, but then moved to subsidized housing. There is no record of Norman having ever married in the UK. His mother was a sales clerk and his father was a railway worker.

The more one knows, the less one knows

"Neighbors recognized Karl as the Norman they knew, and said he was nice, but an oddball," said Siebert, who explained that one reason why Karl might know so much about luxury cars is because he apparently used to work for some high rollers in casinos and nightclubs. "The neighbors said he wore the uniform of a casino worker and drove around in a golden Rolls Royce. But I find the more I ask about Karl's past, the less I know about him.

"The memory Karl has of his own past is not the past that we know," said Siebert, who had also spent time with Karl in Odenwald, where he is known as Herr Frankfurt to the locals.

"I hope the officials can find a solution for Karl to remain in Germany," he said. "It should not be up to the authorities to define who he is, but for him to define himself."