German police have found a teenager missing for more than two years, in a cupboard in the home of a man suspected of child pornography offences.
The boy, 15, was found in the apartment in the town of Recklinghausen on Friday as officers were searching for pictures of serious child abuse, police say.
He has been taken to a clinic where his psychological state is being assessed.
The man, 44, was taken into custody on suspicion of a serious sexual offence, and data drives were seized by police.
A 77-year-old man who also lived in the apartment was questioned by police before being released.
Police said there was evidence the boy had been in the apartment for a long time but there was no initial indication he had been held against his will.
How did the boy disappear?
As a result of a family crisis, he had been living in 2017 in a shelter in a suburb of Recklinghausen, 100km (62 miles) north of Cologne, German media report.
One day that summer, when he was 13, the boy disappeared after saying goodbye to one of his carers.
Social workers reported him missing and an appeal was made on television but nothing further was heard from him until Friday.
His mother spoke to German tabloid Bild am Sonntag after being reunited with her son.
She said she had barely recognised him and that he looked like a "broken old man". He was, she said, still wearing the clothes he had had on him the day he had disappeared.
According to German media, he told his mother he had been locked up for two and a half years and not allowed to go outside.
His mother said she hoped to be able to visit her son at Christmas.
What happened to the suspect?
He was brought before a judge on Saturday after an arrest warrant was issued for the serious sexual offence.
According to a police statement released on Friday, the man's flat was searched after he came under suspicion of distributing child pornography.
A dog trained to sniff out hard drives was used as part of the search.