More than 700 school employees committed or were alleged to have committed sexual offences against nearly 1,300 children over the last 20 years, according to a first-of-its kind study of child sexual abuse in Canada.

The report, released Thursday by the Canadian Centre for Child Protection, identified 750 cases of sexual offences (or alleged offences) against "a minimum of 1,272 children" between 1997 and 2017.

The offences were carried out or allegedly carried out by 714 employees working in kindergarten to Grade 12 schools across Canada.

The majority of the offenders (86 per cent) were certified teachers, but other school employees charged with crimes also included educational assistants, student teachers, lunch monitors, volunteers, secretaries, custodians and school bus drivers, the report says.

Nearly 140 offenders had secondary occupations, such as sports coaches and tutors, which provided them even greater access to children, the report says.

Many of the offenders included in the study groomed their victims in order to build trust and spend time alone with them, according to the study. Those offenders manipulated their victims to reduce the likelihood of the child reporting the abuse, the report says.

The study also found that a lot of the grooming took place online or by electronic communication, such as text and email.

“School personnel have a privileged position of trust with children. When that trust is abused, that betrayal is extremely damaging to a child,” Noni Classen, Director of Education at the Canadian Centre for Child Protection, said in a news release.

She added that sexual abuse has “lifelong impacts” on the child victims, as evidenced by statements made in court.

“They were left feeling shame, anxiety and worthlessness, when they should have been enjoying childhood,” Classen said.

Among the study's findings:

87 per cent of the offenders were male

75 per cent of the child/student victims were female

55 per cent of the victims were sexually abused on school property (including field trip locations and school buses)

29 per cent of the victims were abused in the offender’s car or residence

More than two-thirds of all victims were high school students

73 per cent of offenders identified in the study were charged with at least one criminal offence

Of the cases that went to trial, 70 per cent resulted in findings of guilt

The Canadian Centre for Child Protection calls the study’s findings “unquestionably alarming” and offers a number of recommendations for change.

The recommendations include setting “appropriate boundaries” between adult school employees and students, such as making it clear that texting students or engaging with them on social media is inappropriate.

The report also recommends mandatory sexual abuse prevention training for educators, school personnel and students, as well as awareness education for parents.