But there is still no sign of his 48-year-old mother, Melanie Batty, who is accused of abducting her own son when he was just 11.
Alex’s official guardian until he turns 18 next year is his grandmother, Susan Caruana, 68, and she regularly complained about Ms Batty’s behaviour.
An investigating source in Toulouse, France, said: ‘The boy claims that his mother has gone to Finland to see the Northern Lights, so the search for her is continuing across Europe.
‘This does not mean that the search has stopped in France – she has been placed here regularly over the years, and may well still be hiding in the countryside. All kinds of information is circulating, and a lot of it does not add up.’
Focusing on Ms Batty, the source said: ‘If she did travel to Finland, then she would absolutely have needed a passport. This would make tracing her journey relatively easy.’
Interpol has been involved in the increasingly complicated case since Alex went missing in 2017 during a holiday to Spain.
He was with his mother at the time, as well as his paternal grandfather, David Batty, who would now be 64.
There are claims that Mr Batty died six months ago, but his death has not been confirmed.
No record of Mr Batty’s death has been filed, and neighbours in the hamlet of La Bastide, near Carcassonne, said they saw him looking fit and well within the last two weeks.
Greater Manchester police flew to south west France to collect Alex – who turned himself in to French police last Wednesday – but for diplomatic reasons could not assist the French in looking for Mr and Ms Batty.
The French source said: ‘The British are now leading the investigation, and they of course will be interviewing Alex at length. His mother is crucial to the enquiry, and she needs to be found.’
The search area in France alone is a huge swathe of Pyrenean countryside that is hugely popular with spiritual communities, sects, cults and hippies.
It is understood that the community the Battys joined never stayed anywhere for more than a two weeks before moving on, living off the land and whatever money they could pull together.
Rolande Alibert, the mayor of La Bastide, described Alex as a ‘happy and polite’ boy who would be ‘happy to be back with his grandmother.’
Mr Alibert said: ‘We knew the boy as Zak and his grandfather as Peter, and it was only after I read about them in the newspaper that I learned the truth.’
Alex landed in Manchester on Saturday evening, walking off the plane with a skateboard under his arm before joining his grandmother.
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