A schoolboy from County Durham is fighting a court battle to remove his name from the Sex Offender Register after he admitted to "smacking girls' bottoms and pinching bra straps".
Two High Court judges heard that the boy, aged 15, had also confessed to touching two girls on the breast area outside their jumpers, has lost all his friends and become suicidal after being placed on the register.
His father told the judges in London that, although the boy initially regarded his misbehaviour as "horseplay", he rightly changed his attitude when interviewed by the police.
But in addition to the serious "slap on the wrist" he had expected in the form of a final warning from police, his son was required to record his name on the register for two-and-a-half years.
The father claimed that, before his son confessed to the assaults, no warning was given that he could end up on the register.
Lawyers for the boy, referred to in court only as "R", are seeking judicial review of the decision of Durham Police to refer him for registration.
In a parallel case, a boy of the same age - referred to as "U" - who admitted putting his hand up a girl's skirt, is challenging a similar decision by the Metropolitan Police.
Lord Justice Latham and Mr Justice Field are being asked to rule that the power to "list" unconvicted juveniles under the 1998 Crime and Disorder Act is incompatible with Articles 6 and 14 of the European Convention on Human Rights.
This guarantees the right to a fair hearing and the right not to be discriminated against on grounds of age.
In the case of U, it is also alleged that the boy was induced into confessing by a police constable's promise that he would be issued with a warning rather than being prosecuted, but he was not warned that his name might end up on the register.
The 1998 Act introduced a new system of reprimands and warnings to be administered when a young person with a clean record admits an offence and a police officer considers that, although he has evidence which would probably result in a conviction, it would not be in the public interest to prosecute.
Boy R's father told the judges: "I agree he wasn't completely innocent. He had a lesson to learn in life, that he just couldn't go on like that. We tried to help the police in putting him right and we thought the warning was a good idea."
But, he said the "relentless" pressure felt by the boy after he was placed on the register ruined his life.
