The Irish government is to set up a statutory commission of inquiry into sexual abuse at schools run by Catholic religious orders after a preliminary investigation found almost 2,400 allegations of historic abuse.

The investigation, led by a leading barrister, Mary O’Toole, documented 844 alleged abusers in 308 schools run by 42 religious orders across the republic of Ireland.

One hundred and thirty seven people who participated in her inquiry completed in-person interviews and 12 provided written submissions.

Most of those who took part were men in their 50s and 60s.

The Irish education minister, Norma Foley, described the report as a “harrowing document, containing some of the most appalling accounts of sexual abuse”.

The inquiry was launched in 2022 after an RTE radio documentary highlighted historic sexual abuse at the fee-paying Blackrock College, a Dublin school associated with many Irish rugby internationals and leading businessmen.

Fifty-seven people have alleged they were abused there.

In November 2022, the Spiritans in Ireland, who ran the school, apologised to all victims on behalf of the order.

Allegations were also made against the Jesuits, the Carmelite Fathers, the Christian Brothers, the Sisters of Mercy and the Missionaries of the Sacred Heart.

It is understood that religious orders’ records indicate that more than half the 844 men accused of abuse are known to be deceased.

Those interviewed for the scoping inquiry described being molested, stripped naked, and drugged amidst an atmosphere of terror and silence.

Some spoke of their strong belief that the abuse was so pervasive that it could not have gone unnoticed by other teachers or senior members of the religious orders.

Several survivors said that while they had been successful in their careers, that was because they had worked excessively and at the cost of close, personal relationships, in order to distract themselves from their childhood trauma.

Foley and other ministers have paid tribute to the survivors for speaking up about their experiences.

“This report reveals the severe impact of sexual abuse on the lives of survivors,” she told a news conference. “It is vital (that) the needs of survivors remain at the heart of our response.”

The government will have to find someone to chair the proposed statutory inquiry, which ministers say will have wide-ranging powers.

The cabinet will also have to establish its terms of reference, including whether to include non-Catholic run schools.

It could be several years before the proposed statutory commission of inquiry publishes its findings.