The father at the centre of the Ruinerwold farmhouse mystery will not appear in court next week for a preliminary hearing into charges of sexual abuse and holding people against their will, his lawyer has told the Telegraaf.

Gerrit Jan van D, who lived with six of his children in isolation for some nine years, is not well enough to talk and remains in prison hospital in Scheveningen, lawyer Robert Snorn told the paper.

Van D had a stroke several years ago and was not treated at the time. Since then he has apparently been bed-ridden and unable to speak. He responds to questions by nodding or shaking his head, Snorn said.

Josef B, the Austrian man who rented the farmhouse on behalf of the family and is suspected of kidnapping and money laundering will be at the hearing, the paper said.

The family were discovered in early October when one youngster went to the local bar, appealing for help.

At the time the family was portrayed as some sort of doomsday cult with no connection to the outside world, but it emerged later that both the father and the eldest son were active on social media.

It also transpired that Van D had three other children who had broken contact with him and never lived in Ruinerwold. He is suspected of sexually abusing two of them.

At the end of last year, the four oldest children put out a joint statement via documentary film maker Jessica Villerius, saying that they support the complaints made against their father, who also faces charges of kidnapping and money laundering.

But the five youngest children say they back their father and describe the division between them and their older siblings, in the statement, as ‘very painful’.