The local postal worker said he never once delivered a letter to the home. (AFP image)

Sitting on the terrace at the pub, in the small village of Ruinerwold in the north Netherlands, the young man looked out of place. He had long, tangled hair and a dirty beard, wearing tattered clothing and appearing perpetually confused. There was something "unworldly" about him, as the bar's owner, Chris Westerbeek, would soon recount to Dutch news outlet RTV Drenthe, and when Westerbeek sat down to talk to him on Sunday, he learned why.

He had not been outside in nine years, he told Westerbeek.

The 25-year-old man was in desperate need of help, he said. He had managed to sneak out of the small, secret area where he and his adult siblings had been kept all that time, living in isolation in a farmhouse just outside Ruinerwold that appeared almost abandoned. He said he had never been to school and hadn't been to the barber in nearly a decade.

"He said he was the oldest and wanted to end the way they were living," Westerbeek said, according to the BBC.

On Tuesday, police answered the man's plea for help.

The family was rescued from the farmhouse this week after a tip from a "young man" who was "worried about the living conditions of his family" led authorities to search the property, police in the Netherlands province of Drenthe said in a statement. Upon arriving, police found a father and his six children living in the small, enclosed space, the statement said. A 58-year-old man described in Dutch media as a "handyman" was arrested on the property for refusing to cooperate with police, who said they do not know the man's relationship to the family at this time. The children told investigators they were all adults, which police said will "of course be further investigated."

Citing unnamed sources, RTV Drenthe reported they had been living under the impression that they were the only people left in the world. They were waiting for "the end of time," the news outlet reported.

Officials did not confirm reports regarding the family's beliefs, saying the case was still under investigation.

"Our primary concern is for the family members," a police spokeswoman told the Guardian. "What exactly happened in the farmhouse is still very unclear. We are exploring all possible scenarios."

From a distance, the farmhouse yard looked unkempt, with sheds and untrimmed shrubs, neighbors who lived down the road told local media. The home is a few dozen meters off the main road, accessible only by crossing a bridge over a small stream, then driving up a dirt road until reaching a gate. Sometimes the neighbors saw a dog, a goat and geese outside - but never children.

The local postal worker said he never once delivered a letter to the home.

"It's actually pretty strange, now I come to think about it," he told the Dutch news outlet Algemeen Dagblad, according to the BBC.

Inside, the family was self-sufficient, subsisting on vegetables from the garden and a goat, and possibly with help from the 58-year-old tenant, Dutch media reported.

He was the only one neighbors ever saw outside, coming and going in a blue Volvo, not talking to anyone.

"We always thought that one man was living in the house who was renovating the place," one neighbor told the Guardian. "We had no idea."

Some local carpenters knew the 58-year-old man as a gifted furniture maker and woodworker who kept his personal life to himself, the newspaper Dagblad van het Noorden reported. But his reclusive nature led some neighbors to grow suspicious of what might be going on behind the gate.

"No one ever came to his yard. We thought: It must have something to do with hemp cultivation or something," a neighbor who said she met the man only once told Dagblad van het Noorden. "But this? We never suspected this."

When police arrived to investigate, they found a secret area that had "a number of rooms with makeshift furnishings where a family was living an isolated existence," the local mayor, Roger de Groot, said during a news conference, the Guardian reported.

None of the family members were registered with the local government, police said, meaning there was no way to know they existed. The owner of the farmhouse, a prominent local figure, said she was "speechless," believing she had been renting the home to a single 58-year-old man for years and having "no idea" other people were inside, Algemeen Dagblad reported.

On Tuesday, Drenthe police said in a statement that the family had been taken to a doctor and is now being cared for. A "large scale" investigation is ongoing, and authorities are working with prosecutors to consider whether criminal charges will be brought in the case.

De Groot said authorities believe that the children's mother died years ago, but that there were too many questions remaining regarding how the family ended up living this way over the past nine years.

"I've never seen anything like it," de Groot said.