Schools are failing to comply with their child protection duties by unofficially and illegally excluding "difficult children", a think tank has warned.
The schools in questions are failing to follow legal protocol by persuading parents to remove their children, rather than officially excluding them.
The report by the Centre for Social Justice (CSJ) accuses schools of manipulating the current system to exclude what they describe as "society's most vulnerable children and young people".
Figures from last year show around 5,740 pupils were permanently excluded and 331,380 were excluded on a fixed-term basis, numbers that the CSJ describe as a "significant majority".
The report states: "Many pupils are being profoundly misunderstood within some mainstream schools. The underlying causes of their behaviour, and their needs, are not being addressed properly. As a result, there is a near-hidden group of children and young people in our education system which is being failed."
The think tank blames a lack of transparency as well as insufficient monitoring by schools, local authorities and the Department for Education and calls for action to be taken immediately.
CSJ Executive Director Gavin Poole said: "It is vital that unscrupulous and sometimes illegal practices indulged in are confronted head on. The money for these ‘ghost pupils’ is retained by the school, but don’t attend, with some schools failing to provide any suitable education or support to these children."
According to the CSJ, there is a strong correlation between exclusion, poverty and disadvantage, with special educational needs pupils, minority ethnic groups and lower socio-economic groups more likely to be excluded.
One case study from the report exposed a disturbing trend for schools to expel "difficult" children whose problems are far more complex than simple bad manners.
"In one school, we learnt of two brothers (two of eight children who have four different fathers). When they were aged five and seven, one of the fathers tied all of the children up, tortured them and then fatally shot himself in front of them. Each of these boys had been excluded from their primary schools by year four."
The report refers to the "common practice" of teachers telling parents that their child will be permanently excluded, suggesting this can be avoided if they educate him or her at home.
In light of the report's shocking statistics, David Cameron's answers to cracking down on truancy, which he aired in his education speech last Friday, seem simplistic and misinformed. To call for benefits to be taken away from parents whose children truant is by no means addressing the problem and the cause of truancy runs far deeper than a child's mere dislike for school.
The CSJ report also highlights a recent survey “of 15 to 18-year-olds held in custody,” which presented appalling findings in relation to their educational background.
It said: "Ninety per cent of the young men and 75 per cent of the young women had been excluded from school, and more than seven in ten had truanted from school."
The think tank also refers to the number of "harrowing examples" and "distressing accounts" of domestic violence against children, which led to aggressive behaviour. This could also lead to exclusion from school.