Over a quarter of girls in special secondary education have been forced to commit sex acts against their will, according to research published on Thursday by the sexual health groups Rutgers Foundation and Soa Aids Nederland.

The research is based on the experiences of 1,113 youngsters in some form of special education. Among the general school population, 7% of girls report having been forced into some form of sex, earlier surveys show.

Most offences centred on intimate kissing or touching, but 13% of special education girls said they had been forced to have full sex, the paper said.

‘We were shocked by this,’ senior researcher Hanneke de Graaf told the paper. ‘This is a significant difference to the situation in ordinary schools.’

Girls in special education are more likely to have behavioural disorders such as autism and may be more naive than girls in the regular school system, she said.

They are also four times as likely to send nude photos or sex films to other people, the survey found.