Jon Coles, the director-general of schools at the Department for Children, Schools and Families, told a conference that 16-19 year olds not in employment, education or training - so-called Neets - face "real dangers and a downward spiral that can lead to them dying very young".
Coles cited DCSF research carried out in one northern city two years ago that revealed 15 per cent of its long-term Neet population had died within ten years of falling out of the system. The Times Education Supplement reported that Mr Coles told the conference this research was "profoundly shocking" and showed that there was a very clear "social cost" of being outside the system of education and training.
The latest official figures show that there are 207,800 Neets in the UK - 10.3 per cent of the age group. This is up nearly a third on the number when Labour came to power in 1997.
A DCSF spokesman said that the research cited "could not be taken as representative of the whole country". However, he added: "It is clear that Neets are at greater risk of poor health and negative outcomes in later life."
The DCSF declined to reveal further details about the study.