A “legal loophole” has been condemned by a children’s charity after almost 40 sex crimes by adults in a position of trust were recorded across the Thames Valley.

Official data showed there were 38 sexual offences committed by adults in a position of trust since 2011 across the region.

But the NSPCC fears the true extent of abuse is much worse because the law does not apply to youth work roles such as sports coaches and leaders of religious groups.

Figures from the NSPCC revealed a 57 per cent increase in recorded Abuse of Position offences in England and Wales where professionals such as teachers or care staff have sexual contact with 16 or 17-year-old children they work with.

Charity bosses said a legal loophole means adults with regular contact with children in sport and other activities are able to groom them from a young age and abuse the “trusting” relationship to have sexual contact as soon as the child turns 16.

Lee, whose name has been changed to protect his identity, was befriended by Adam, whose name has also been changed, at his church group when he was 15.

Adam began texting Lee and asking to spend time together outside of the group.

Lee said: “Adam started by sitting closer to me on the sofa, trailing his finger on to mine. Things which I thought were weird but not big enough to react to.”

Things escalated to kissing and sexual contact when Lee turned 16.

He added: “I was so confused but knew what he was doing was wrong. I wanted it to stop but part of me was afraid to speak out because I didn’t want to get him in trouble.”

NSPCC’s head of policy, Almudena Lara, said: “Safeguarding in children’s clubs should not end suddenly at 16. The NSPCC has been told of a number of cases where in sports and other youth work settings, leaders have used their position to groom children, and then take advantage of them as soon as they turn 16.

“It is baffling that sports coaches and other youth workers are not deemed to be in a position of trust, given the significant responsibility, influence and authority that adults in these roles have over the children they are there to look after.

“Sadly, we know that this trust can be abused and it is therefore vital that this legal definition is widened to include sports coaches and other youth workers, bolstering protection for teenagers at risk of grooming once they pass the age of consent.”