A teenager has been cleared of sexually assaulting a girl under a desk in a school classroom.

Prosecutors claimed the boy touched the complainant’s crotch against her will and tried to put his hand into the waistband of her tights during a class at the secondary school.

The school is within Sutton borough but can not be identified for legal reasons.

The boy, 15 at the time of the incident, denied the sexual assault or touching her intimately.

He admitted only stroking the inside of a girl’s thigh, but denied it was not consensual.

He was found not guilty of sexual assault at Croydon Youth Court on Thursday.

Magistrates said as the complainant had not raised the alarm at the time of the alleged assault, instead waiting until after class to tell a teacher, they were satisfied her silence meant consent.

The mother of the 16-year-old complainant said she had since pulled her daughter out of the school as she could not “trust their system to protect her”.

Neither parties nor the school can be named for legal reasons.

During a trial last week, the court heard in September last year the two teenagers were sitting next to each other in a classroom with more than a dozen others when they accidentally touched arms, which the defendant took as flirting, and began stroking the complainants leg under their desk.

Defence solicitor Chris Studdert argued the complainant had also been stroking the defendant’s leg, something she repeatedly denied when being cross-examined via a video link.

Mr Studdert said there had been a “reluctant acquiescence” on her part and that she had not “given him a signal to stop in a way he understood”.

Prosecutor Sylvester Folorunso, told the bench: “When a young female is intimately touched, they do not always raise the alarm at the point it is happening, she still went to a person of authority after class to complain.”

Mr Studdert said the case had been a “tragedy for both of them” and that it was “a pity this matter had not been sorted out firmly by the school, which would have saved a day in a criminal court.”

Lesley Budge, chairwoman of the bench, said: “We do not feel the Crown Prosecution Service has proved its case to us beyond all reasonable doubt.

“The incident was not planned, but came about a result of close seating arrangements.”