The study, conducted jointly by the Universities of Zurich and Cambridge, revealed that nearly eight percent of girls and four percent of boys aged between 15 and 17 years had been forced into sex or fondling, newspaper Tribune de Genève reported.

The percentages were significantly greater for peer-aged abuse than for abuse by a family member, with two per cent of girls and less than one per cent of boys reporting abuse within the family context, wrote newspaper Tages Anzeiger.

Approximately 42 percent of juvenile victims reported that the abuse had taken place either with a current or former romantic partner.

Most often, the perpetrators attended either the same school or disco.

The study found that “the vast majority of rape cases were committed by a person of similar age, with whom the victim was in a love relationship or at least knew well,” study co-author, Manual Eisner from the University of Cambridge, told newspaper Tages Anzeiger.

Both boys and girls reported equally that the perpetrators had been considered a good friend. Most of the perpetrators were recorded as being male.

In Switzerland, 6,700 pupils were surveyed to reveal that one in every five girls and one in every ten boys reported bodily sexual abuse, defined as kissing or caressing of intimate body parts, attempted or completed penetration by body parts or objects in the vagina, mouth or anus.

Sexual harassment of a non-tactile nature was also shown to be prevalent, with cyber-bullying becoming increasingly common. Approximately 40 per cent of girls and 20 per cent of boys recorded having been subject to verbal or written sexual harassment, exposure to pornographic material and such like.

Some perpetrators even posted pictures of their victims’ intimate parts on the internet.

“This behaviour has massive negative consequences for the reputation of the young person,” Eisner said.

But only some five percent of victims filed any report with the police.

“The victims suffer enormously,” Pasqualina Perrig-Chiello, professor of developmental psychology at the University of Bern and a member of the Scientific Advisory Committee for the study, told Tages Anzeiger.

Perrig-Chielloi reported that in most cases, shame, fear of retribution or the sense that the abuse was the victim’s own fault, prevented individuals from speaking out.

She is glad to have gathered the data.

“We knew already that there are many sufferers. Now we finally have it in black and white,” she said.