The arrests follow complaints made by nearly 20 former pupils of Sacred Heart College, Carrignavar.

Gardaí received the first of the complaints last August, when they were approached by a former boarder at the secondary school.

Two of the three men were arrested and questioned at Cobh Garda Station in Co Cork, while the third was detained in Dublin.

The three, described by Garda sources as “elderly”, were questioned in relation to allegations made by former pupils who claimed they had been sexually abused at the school in the 1970s, 1980s, and early 1990s, when it was run by the order of the Missionaries of the Sacred Heart.

The complaints were made against four former members of staff, one of whom has since died.

Gardaí from Cobh and Glanmire have been involved in the lengthy investigation, along with detectives from the National Bureau of Criminal Investigation based at Harcourt Square, Dublin.

Some of the victims alleged that they were subjected to repeated abuse over some length of time, but gardaí said there was no evidence to suggest that they were passed around by their alleged abusers.

While some of the alleged victims still live in Cork, Kerry, and Limerick, others have moved to counties much further north. Gardaí travelled to interview them as part of their painstaking investigation.

They also travelled to interview other former pupils who the alleged victims said would substantiate their stories.

Some of the victims went to the gardaí after meeting counsellors from the One In Four support group, which helps people who have suffered from sexual abuse.

One In Four hosted a special counselling session in Cork last October to deal with allegations of child sex abuse at Carrignavar College.

Garda sources confirmed yesterday that the men were released without charge and that a file will be forwarded to the DPP.

The National Board for Safeguarding Children in the Catholic Church has completed an audit of child protection practices within the Missionaries of the Sacred Heart late last year.

Whether the report will be made public or not depends upon the missionaries. They have indicated that they will not consider putting anything into the public domain until criminal investigations have concluded.

Last August, the HSE also began an investigation into child protection practices at the school.

The inquiry was ordered by Children’s Minister Frances Fitzgerald after the Irish Examiner was inundated with letters, phonecalls, and emails from former pupils who say they endured routine violence during their time at the then boarding school.

Allegations of physical and sexual abuse at the school first emerged when Fianna Fáil’s Mark Daly raised questions about the order’s supervision of a former teacher at the school who’d been the subject of numerous abuse allegations.

Settlements were made by the order in two civil cases taken against the priest.