The Children's Commissioner Dr Maggie Atkinson believes there are illegal exclusions where children are sent out of school but nothing is recorded about their absence.
Worse, no alternative education is put in place for them. She thinks they may not feature on the nation's radar.
Excluded kids are usually disruptive kids. They may also be hostile and rude.
But they still need an education.
They are also the preoccupation of today's educational thinkers and policy makers who have realised that excluding kids from school and then effectively abandoning them on the streets is a sure way of raising an army of troublemakers.
When I interviewed two young excluded lads in Sheffield last week it was apparent to me immediately that their education - at the age of 15 - was effectively over. They had tried the patience of their teachers beyond measure and disrupted the education of their class mates. They both came from chaotic homes with appalling role models.
Easy to see why then, they were spending most of their days OUTSIDE the school gates rather than inside them. And what were the streets teaching them by way of education?
"I end up hanging round with kids twice my age" said 15 year old Connor. "I started smoking weed and doing real naughty stuff. I'm getting in worse trouble."
"I wish I could go back and learn but it's too late," said his friend Levi, also 15, accepting that his days of learning anything useful and within the law were over.
The parents of his hard-working classmates would no doubt cheer. But who is cheering for Levi? Levi and Connor are just a couple of the 23,000 kids currently permanently excluded from school and in "alternate provision" or AP. Where AP works well it can be a mixture of supervised home learning, car mechanics, apprenticeships or college education. Where it doesn't work it means effectively AN - or Absolutely Nothing.
Connor had five weeks during which that's exactly what he did - wandering the canals and shopping malls of Sheffield City Centre. Now he's lucky he if gets a couple of hours a week of English and maths.
Jane Evans is an educational policy advisor for the charity Barnados. She says that excluding children from chaotic homes doesn't help them. "Early intervention is the key to persistent disruptive behaviour," she told me.
Barnardos is successfully working with schools in Blackpool and Weybridge to keep disruptive kids in school and learning. Last week I revealed that one in three of those convicted in last summer's riots were children who had been excluded from school. This was a fact which inspired the Department of Education's Advisor on Behaviour Charlie Taylor to examine how to improve provision for these difficult children. His report concentrated on Pupil Referral Units and was highly critical of the low standards and low expectations found in these units which he said was failing a generation of our neediest children.Around 14,000 excluded children are sent to PRU's"If we don't help these children, if we don't educate them, we are fuelling a cycle of crime," he told me. Connor and Levi already both have criminal convictions. Connor's dad is in prison. He doesn't want to end up there himself. But the education he is receiving on the streets instead of in school isn't going to do much to stop him ending up like his dad - behind bars.