He walked out of a German forest, speaking English and knowing only his first name. Police in Berlin are trying to unravel the mystery of a teenager who says he has no idea who he is or where he comes from.

The boy presented himself to the Berlin authorities last week saying all he knew was that his first name was Ray, he was probably 17 years old and he and his father had roamed through the woods for about five years.

"He speaks fluent English and very broken German," the Berlin police spokesman Michael Maaß told the Guardian. The police have not yet determined if his accent is American, British or that of some other English-speaking nationality.

He told youth workers that his father, whom he called Ryan, had died two weeks ago and he had buried him in a shallow grave covered with stones. The boy then walked north, following instructions his father had given him should anything happen to him.

The pair's odyssey started after his mother, who he said was named Doreen, died. He says that he and his father never set up home but kept moving, staying in tents and huts in the woods.

It is not clear what they ate or how they survived the often harsh German winters. "He doesn't show any signs of abuse and he is in good shape physically and psychologically," Maaß said.

The boy says he cannot remember anything about where he lived before the five-year journey began. "We have nothing more to go on than what he told us. We don't have any other clues as to his identity," Maaß said.

The Berlin police have appealed for help to all European countries via Interpol to see if any outstanding cases of missing persons might match the boy's description. They have not released a photograph of him at this stage.

He is currently in the care of Berlin's youth services and they will decide what happens to him next if his identity is not established.

The boy's story recalls European folk tales of feral or wolf children being brought up in the forest or in isolation. One real case was that of Kaspar Hauser, a teenage boy who appeared suddenly in Nuremberg in 1828, claiming to have been raised in a darkened cell without any human contact.

It is also not the first time an English-speaking stranger has turned up in Germany. In 2006 an English-speaking man in his early 60s appeared in Mannheim train station saying that apart from his first name, Karl, he had no idea who he was or where he came from.

The police concluded he was suffering from amnesia and while they never discovered his identity, they believed he was genuine.

That was not the case, however, with the so-called piano man, who turned up on a beach in Kent in 2005, seemingly unable to speak and only capable of communicating by drawing and playing the piano. For months his true identity was a matter of intense speculation. Finally he broke his silence, revealing that he was in fact a 20-year-old from Bavaria, called Andreas Grassl.