(CNN) -- German police have released a photograph of the 17-year-old known only as "Ray" who turned up at Berlin City Hall last year after claiming to have been living in the woods for five years.
The release of the photograph, along with details of his appearance and scant possessions at the time of his discovery, is part of an effort by German authorities to unravel the mysterious identity of the boy who speaks English and a little German and what is his family background.
The boy only knew his name, his date of birth of June 20, 1994, and his parents' first names.
After months of investigation, German authorities said they are stumped on who the boy really is.
The boy named Ray told authorities upon his discovery last September that he had been living in the woods with his father, Ryan, but decided to come out of the wilderness after his father had died, investigators said. The boy couldn't explain why his father died, authorities said.
Investigators have been unable to find the father's body as the boy was unable to name or show the place he buried his father in the forest underneath some stones, officials said.
"They were hiking with the help of maps and a compass only and stayed in tents or caves overnight," Berlin authorities said in a statement released Tuesday.
The boy provided police with "some vague information" about his mother, saying her name was Doreen, and he wore a golden-colored necklace around his neck with the pendant "D," the first letter of his mother's name, police said.
His mother died in a car accident when the boy was 12 years old, but he doesn't remember the details of the accident, authorities said.
The boy presumes the scars on his face were caused by the accident, police said.
After his father also died last August, the boy roamed north for five days until he arrived to Berlin City Hall and asked for help last September 5, authorities said.
The teenager cannot "specify anything about cities, countries or regions him and his father had travelled through," authorities said in a statement.
German authorities have been trying to establish the boy's identity through Interpol. A guardian has been appointed, authorities said.
"The Youth Office and the Berlin Police have great doubts on the boy's story. That is the reason why the Youth Office now decided to publish a photo of 'Ray' and ask for your help," authorities said in a statement.
In releasing a photo of the boy, taken last September, authorities also provided a physical description of him: 16 to 20 years old; about 5-foot-11 or 180 centimeters; dark-blonde medium length hair; blue eyes; athletic physique; teeth, fingernails and hands all conveying a neat impression; three scars on his forehead; three small scars on his chin; one scar of 1 centimeter in length on his right arm; and a complete set of teeth with no dental work obvious.
The boy is able to read and write and spoke mainly in English with a few words in German, authorities said.
He carried a Freetime Alpes 2 tent designed for two persons; an Outwell sleeping bag; a black-like new backpack of the Finnish brand Kaikkialla; and clean clothes, partly for winter, authorities said.
The story has been compared to the "Piano Man," who was found wandering aimlessly near a beach on the isle of Sheppey, Kent, in southern England in 2005. The man was wearing a waterlogged dinner suit with all its labels cut out and a tie. It initially was reported that he stunned witnesses with a "virtuoso performance" on the piano.
The man was identified as a 20-year-old German national from Bavaria after telling staff at a hospital that he had been attempting suicide when found by police, the Times of London reported in August 2005. The man could not play the piano as well as initially reported, the newspaper said.
The man, whom authorities did not identify because of confidentiality laws, flew back home to Germany, the Times said.
CNN's Bharati Naik contributed to this report.