British teenager Alex Batty, who was found in France after being missing for six years, has returned to the UK, Greater Manchester Police has said.
Alex, his mother and grandfather all vanished in 2017 while they were on holiday in Spain.
His mother does not have parental guardianship of the 17-year-old and her current whereabouts are unknown.
The force said at a press conference it is yet to establish the circumstances about his disappearance.
Police are yet to determine whether there will be a criminal investigation.
Alex was found on Wednesday by a motorist, who spotted him on a road in the foothills of the French Pyrenees, near Toulouse.
Speaking at a news conference on Saturday night, GMP Assistant Chief Constable Matt Boyle said Alex was met at Toulouse airport by a family member and specially-trained officers earlier, before flying back to the UK.
“This moment was undoubtedly huge for him and his loved ones and we’re glad that they have been able to see each other again after all this time.”
GMP said as it had not obtained formal statements from Alex, it could not comment on details disclosed by French authorities about what he may have been doing while he has been missing.
“Speaking with him at a pace that feels comfortable to him will ultimately determine how this case is progressed and whether a criminal investigation is to ensue,” ACC Boyle added.
“We are yet to fully establish the circumstances surrounding his disappearance.”
Alex is believed to have been living a nomadic lifestyle in spiritual communities with his mother and grandfather for the past few years.
Melanie and David Batty left Greater Manchester with Alex for a pre-agreed week-long holiday to Marbella in Spain on 30 September 2017.
He was last seen at the Port of Malaga on 8 October that year, the day they were expected to return to the UK.
It is understood that, since that time, Alex had been living in the remote Pyrenean valleys, travelling about from place to place in a kind of itinerant commune.
The area in the foothills of the Pyrenees is known for attracting people in search of alternative lifestyles.
Residents of the small hamlet of La Bastide in the Pyrenees have told the BBC that Alex had been staying at a guesthouse on and off for the past two years.
French officials said he decided to leave when his mother wanted to go to Finland.
Alex is believed to have walked through the mountainous terrain of southern France for four days before being found by a delivery driver in the middle of the night.
The driver, Fabien Accidini, said he lent the teenager his phone and let him use his Facebook account to contact his grandmother, Susan Caruana.
“I cannot begin to express my relief and happiness that Alex has been found safe and well,” she said in a statement issued by police on Friday.
She added it was “so good to hear his voice and see his face again”.
She requested privacy for the family, so that they could “make his return as comforting as possible”.