At least one in seven children are being pressured into pleading guilty to offences when they are innocent, a groundbreaking study has found.

       The Exeter University research found children under 18 were pleading guilty to avoid heavier punishments, because of pressure from parents or friends, or simply to avoid further time in custody.

       Lawyers questioned by researchers estimated that 15 per cent of children who pleaded guilty were actually innocent, although some suggested the figure could be as high as 60 per cent.

       The researchers also interviewed 19 children who had pleaded guilty, of whom only two were happy with the punishment they received. At least seven, more than a third, were unhappy, suggesting they were actually innocent.

       The data suggests more than 1,500 – and potentially 3,000 – children are pleading guilty every year when they are innocent of offences. It means they can be left with an offence record that can limit their job chances through criminal record checks and be referred in any future court proceedings.

       The children were asked to rank the reasons for why they admitted the offences, and actual guilt was only the sixth most important factor.

       Top was advice from their lawyer, avoiding a worse sentence at trial, the future consequences, family pressure or getting the trial over. Sixth was "factual" guilt, followed by the probability of conviction, financial consideration and advice from peers.

       One barrister told esearchers the lure of a referral to a community sentence could be too great to resist, saying: "It's difficult to advise against the guilty pleas when you're going to get a referral order in the bag as opposed to risking going further."

       For lawyers, factual guilt was still only the fifth most important factor. The research said the criminal justice system incentivised guilty pleas by children because of guidelines that those who admit an offence at the first stage of proceedings can get their sentence reduced by up to a third.

       Second, children may be able to get charges against them reduced if they plead guilty, since prosecutors may be willing to drop or reduce charges against them. Pleading guilty avoids the need for the child to participate in a full trial, and makes resolving their case significantly quicker and easier.

       "This incentive to plead has the potential to be particularly important for children, who are often overly sensitive to short-term benefits, and who find the criminal justice environment particularly challenging," said the researchers.

       They recommended that lawyers working with children should have specialist training, and children should not face custodial sentences on conviction at trial if they have pleaded guilty.

       Penelope Gibbs, a director at Transform Justice, said: "Teenagers are particularly susceptible to pleading guilty to crimes of which they are innocent or have a viable defence. Yet the consequences of pleading guilty are life changing.

       "As well as being labelled as a criminal, the teenager will acquire a criminal record which may stop them getting a job decades later."