British children as young as two have been taken to war zones, becoming obsessed with guns and “shooting people”, and indoctrinated into terrorist ideology and hating the West, court papers show.

The disturbed Muslim children, some radicalised in the UK and others returning from Syria and Iraq, were exposed in an investigation into the secretive family courts by The Sunday Times.

At least 20, including a boy who was just one, have been taken away from their parents at some point by authorities.

One girl in her mid-teens from East London, who was removed from a plane bound for Syria, had become “immune to brutality and death” after consuming Islamic State propaganda.

A boy of just five years old become so brainwashed by fundamentalist, anti-Western views, he shouted a phrase meaning “shame” at women he saw not covering in an Islamic burqa or veil.

Another girl of just five years of age was filmed chanting an apparently pro-Osama bin Laden chant by her parents, and her mother’s phone pin was 0911.

Yet, the most disturbing case involves a two-year-old boy whose mother took him to live in the Islamic State capital of Raqqa in Syria, where he posed alongside an AK-47 assault rifle and dressed as a terrorist.

He was assessed by a social worker and a doctor on his return to Britain in 2015, and in a judgement later handed down at the Royal Courts of Justice in London, Ms. Justice Russell said:

“There was some evidence before the court that on his return, and subsequently, [the boy] displayed signs of having been emotionally disturbed; his language and his ability to communicate were noticeably delayed and he has shown a marked and persistent interest in guns and ‘shooting people’.”

The judgment continues: “[The boy] had been living in an environment where there were a range of guns and where those weapons were used and brandished by his mother and others.

“The evidence of the social worker is that [the boy] is all too aware of what a gun is and becomes overexcited by the suggestion of guns and shooting, and runs around mimicking shooting and makes noises of gunfire.”

The child now lives with his grandparents and is part of a growing number of Muslim children living in the UK after returning from terrorist territory in Iraq and Syria.

In a further case, three children from Yorkshire were returned to live with their parents, despite them being suspected to attempting to take the pre-teens to Syria, taking them to extremist gatherings in the UK, and filming one performing a terror chant.

Speaking on the case, Mr. Justice Cobb admitted there was a “risk” that “once the proceedings are over and the glare of social work interest has faded, they will revert to their previous ways”.

The court document also revealed the case of a 16-year-old girl from Tower Hamlets, east London, who was stopped from flying to the war zone in 2014.

In her family home, officers found shocking terrorist material and Mr. Justice Hayden, who presided over the case, said the girl had been left “immune to death and brutality” after consuming a “colossal volume” of the imagery.

“She gave some of the most disturbing evidence I have ever heard from a child or, for that matter, an adult,” said Hayden.

“She told me how violent beheadings, point-blank shootings through the brain and images of mass killings no longer had any impact on her.”