A man arrested after a family were found hidden at a remote Dutch farmhouse is suspected of holding them against their will, prosecutors say.
The 58-year-old suspect, named locally as Josef B, will appear in court on Thursday.
He was held on Tuesday for failing to co-operate during a police search at the farm in the province of Drenthe.
Officers found the family after the eldest son ordered beer at a bar in a nearby village.
The son, identified locally as Jan, was not at the farm near the village of Ruinerwold at the time of the search. Police found his five grown-up siblings and a man they told officers was their father.
Police have not yet confirmed that man’s age or identity and have told the BBC it is a question they are trying to solve.
Another man, reportedly Austrian national Josef B, was also at the farm and arrested. Although he rents the property, police do not know his connection to the family.
Dutch prosecutors said the suspect was believed to have been involved in “illegal deprivation of liberty and harming the health of others”.
He was due to appear before an examining magistrate and prosecutors said they were seeking an extension of his custody.
Two properties linked to the inquiry were being searched by police on Wednesday in the village of Zwartsluis, 16km (10 miles) to the south-west of the farm at Ruinerwold.
How were the family discovered?
The mystery unfolded after the eldest of the six children, aged 18 to 25, turned up at a local bar in Ruinerwold and ordered beer, before asking the owner for help, broadcaster RTV Drenthe reported.
Bar owner Chris Westerbeek described how the man had come in, ordered five beers and drunk them.
“Then I had a chat with him and he revealed he had run away and needed help… then we called the police,” he said.
“He had long hair, a dirty beard, wore old clothes and looked confused. He said he’d never been to school and hadn’t been to the barber for nine years,” he told public broadcaster RTV Drenthe. It later emerged that Jan had been active on several social media accounts, posting photos on Facebook of Ruinerwold in the dark earlier this month, and a series of articles about action to fight climate change.
Police went to the farm and found the man’s five siblings, as well as another man and the 58-year-old suspect.
“We found six people living in a small room in the house which could be locked but wasn’t a basement,” they said in a statement late on Tuesday. “It is unclear whether they were there voluntarily.”
Local reports described Josef B as a handyman.
“I’ve never seen anything like it,” local mayor Roger de Groot told reporters on Tuesday. He revealed that some of the family had not been registered locally and also indicated that the 58 year old was not the father.
What do we know about the property?
Ruinerwold is a village with a population of less than 3,000. The farm is outside the village and is accessible by a bridge over a canal.
The farm, which is part-hidden behind a row of trees, also has a large vegetable plot and a goat.
A neighbour told Dutch media that he had only ever seen one man on the farm, no children, and that there had been animals on the grounds, such as geese and a dog.
The local postman said he had never delivered a letter there. “It’s actually pretty strange, now I come to think about it,” he told Algemeen Dagblad news website.
The farmhouse and the surrounding grounds were cordoned off.
It was unclear what had happened to the children’s mother, although the mayor said she had died some time ago.