More than 50,000 people aged 16 to 18 not in education or work have “gone missing” from official statistics and are receiving no support, according to research published today.

It warned that the problem of Neets - young people not in education, employment or training - is much bigger than local authorities realises because tens of thousands of them have “disappeared off the radar”. In London alone, an estimated 15,000 youngsters have “gone missing”.

Richard Brooks, the former director of strategy at the schools inspectorate Ofsted who carried out the research, said: “Over the course of this parliament the quality of local data on these young people has broken down completely. We are massively understating the scale of the problem at local level where it matters the most, and depriving many young people who are out of sight of the help and support they need.”

In a pamphlet published by the Labour-affiliated Fabian Society, Mr Brooks said the official figures are “disastrously wrong”. When councils compile statistics on what young people leaving education do next, they assume that one in eight of those with an “unknown” destination is a Neet. His research found the real figure is between one in three and one in two.

National statistics said there were 148,000 Neets in England at the end of 2013, but only 92,000 were identified at local level – a gap of 56,000. Mr Brooks said the number of “unknowns” rose from just over 71,000 in 2010 to 162,000 at the end of 2013. One factor was that the figures used to be collected locally by the Connexions advice service for young people, but the Coalition removed its ring-fenced grant, so councils now collect the statistics with greatly reduced resources.

The report, “Out of Sight”, called on Sir Andrew Dilnot, head of the UK Statistics Authority, to review this “aberration” and make proposals to the Department for Education. It said a Cabinet minister should have specific responsibility for Neets.

Mr Brooks questioned the public perception of Neets, insisting they were not a “hard to reach” group. He found that fewer than one in four of the 18-year-old Neets is from a low-income family, and fewer than one in four of this group has special educational needs. In contrast, 80 per cent of the lacked five GCSE A*-C grades including English and maths.

Jenny North, director of policy and strategy at Impetus-PEF private equity foundation which co-sponsored the research, said: “This report really highlights the importance of getting key qualifications to avoid becoming Neet. It’s not good enough that only half of pupils currently achieve A*-C in English and Maths at 16.

"It’s even more of a scandal that of the nearly 50 per cent who don’t, so few are given a fair crack of the whip at getting them by the time they’re 19. Educational attainment is the key to employment, and at the moment our educational system, both pre- and post-16, is failing more young people than we realised.”

A Local Government Association spokesman said: “Councils want to ensure every young person realises their full potential and despite these challenges have actually reduced the proportion of ‘unknown’ 16-to-18-year-olds by 14 per cent since 2012. To build on this success, councils urgently need more legal powers to ensure partners [including UCAS]share vital information as quickly as possible and the next Government must devolve all national youth schemes to local areas enabling councils to meet their duties to young people.”

The Department for Education said: "The proportion of 16-18 year olds Neet is at its lowest level since consistent records began. However, we are not complacent and there is more to do to equip all young people for life in modern Britain.