Alex Batty, a British teen who went missing six years ago and was found this week in southwest France, has arrived back in the UK, police said Saturday.

"It gives me great pleasure to say Alex has now made his safe return back to the UK after six years," Matt Boyle of Greater Manchester Police told reporters at the force's headquarters in northwest England.

The 17-year-old earlier Saturday boarded a KLM flight at Toulouse, headed to London via Amsterdam.

He was accompanied by British police officers and a family member, said Boyle.

"This moment was undoubtedly huge for him and his loved ones, and we are glad that they have been able to see each other again after all this time," he added.

Batty will be returned to his maternal grandmother, with whom the British justice system entrusted his custody before his mother abducted him, aged 11, in 2017 while on holiday in Spain.

For six years, including two in France, he lived a "nomadic" life in a "spiritual "community", never staying more than several months in the same place.

The teen was found in the middle of Wednesday night by a delivery driver after he had escaped and was walking along a road for four days, a deputy prosecutor told a news conference on Friday evening.

He is in good health and does not appear to have been abused in the years since his abduction, according to the doctor who examined him.

His mother, Melanie Batty, has yet to be found and could be in Finland, Leroy said.

Alex Batty told investigators he had not suffered any physical violence during the past six years.

Leroy said on Friday that the teenager decided to escape when his mother announced she was going to go to Finland, where she is "likely" to be now.