A couple from Somalia have been accused of keeping their four children at home and trying to brainwash them with videos of Muslim extremism, a High Court judge has said.
The youngsters, aged between 10 and 18, told social workers that they had been made to watch footage which included images of a beheading and a rotting corpse.
They also complained that their parents had shown support for an Islamic State, also known as Daesh, leader and for extremist violence and expressed anti-Semitic, anti-British, anti-white and homophobic views.
Ms Justice Russell has been asked to make care decisions and has revealed detail of allegations in a written ruling following a preliminary hearing in the Family Division of the High Court in London.
She said the children could not be identified and has not said where in Britain the family lived.
The judge said all four youngsters had been removed from the family home and were in local authority care pending decisions about long-term living arrangements.
She said the eldest youngster had raised the alarm by emailing ChildLine.
Police had subsequently traced the email to the family's home.
Ms Justice Russell said the children's parents disputed allegations.
"There are outstanding issues of considerable seriousness in respect of allegations made by the children both as to the extent of the physical and emotional abuse within the family home and as the complaints they have made that their parents tried to brainwash them and to influence them into adopting extremist views, sometimes known as radicalisation," said the judge in her ruling.
"ChildLine received an email complaining of abuse and physical chastisement...
"The children were kept at home, did not attend school and were kept socially isolated only being allowed out once in every three weeks.
"Police traced the email to the family address."
She added: "(Their parents) continue to deny the extent of complaints made of physical chastisement and of making the children watch inappropriate images of extremism on videos such as a beheading by Al Shabaab, and of a rotting corpse.
"The children also said that (their parents) supported Abu Bakr Al-Baghdadi (a leader of Daesh).
"The children have complained that their parents expressed support for extremist violence, and have expressed anti-Semitic, anti-British, homophobic and anti-white views in the home, which the children reject."