Image caption Former pupils speak for the first time about abuse at Fort Augustus Abbey School

A BBC investigation has uncovered evidence of serious physical and sexual abuse at one of Scotland's most prestigious Catholic boarding schools.

Accounts of abuse at the now-closed Fort Augustus Abbey School in the Highlands and feeder school Carlekemp in East Lothian span 30 years.

The BBC has spoken to 50 former pupils about their experiences at the schools, which were run by Benedictine monks.

The head of the Benedictines, Dom Richard Yeo, apologised to any victims.

The programme, BBC Scotland Investigates: Sins of Our Fathers, contains testimony from former pupils, speaking openly, and for the first time, about life with the monks.

TV DOCUMENTARY Sins of Our Fathers will be broadcast on BBC1 Scotland on Monday 29 July at 21:00

Many said they had nothing but good memories of the place but during the six-month investigation, the BBC also heard accounts from old boys of physical violence and sexual assault including rape by monks at the fee-paying schools.

The programme contains evidence against seven Fort Augustus monks. Two headmasters have also been accused of covering-up the abuse.

It contains accounts from five men who were raped or sexually abused by Father Aidan Duggan, an Australian monk who taught at Carlekemp and Fort Augustus between 1953 and 1974.

Image caption From top left clockwise, Chrysostom Alexander, Gregory Brusey, Aidan Duggan and Edward Delepine It was under the bench and I was bending down and he was behind me. He pulled my trousers down and then it was quite horrible … it was painful. 'Sins of Our Fathers': The testimony

Donald MacLeod, who attended Fort Augustus, on the banks of Loch Ness, from 1961, told the programme how he was groomed by Duggan during piano and photography lessons.

He said: "At the time I just felt very, very lonely … I remember that he was … very friendly and when I was playing he'd put his hand on my knee … which at the time I thought was rather nice, being friendly."

Mr MacLeod, who was 14, was then seriously sexually assaulted by Duggan. He raised the alarm about the rape - but was not believed.

He said: "I was called into the headmaster's office and he said that he'd heard that I'd been telling my parents about Father Aidan and that I shouldn't tell these lies and that it's a mortal sin to lie about things like that. And if you commit mortal sin you go to hell."

Brothers Christopher and David Walls attended Carlekemp in the late 1950s from the ages of eight and nine. Both were physically, then later sexually assaulted, by Duggan.

David Walls said: "I was being groomed … the beatings stopped, the sarcasm and the making a fool of you in public and so on, that all stopped, once the cuddling started. So it was a huge relief. And, you definitely felt this kind of sense of gratitude almost."

Image caption The programme contains accounts from five men about abuse by Fr Aidan Duggan

Christopher told the programme: "And it wasn't until later that it fell into place … that was what it was all about - all the beatings and all that was about this."

Fr Duggan returned to Australia in 1974 - and became a parish priest in Sydney. But no warnings were given by the Benedictines to the receiving authorities, and he continued to abuse.

The BBC travelled to Australia to meet another of his victims.

John Ellis was sexually abused by Duggan for several years from the age of 13.

Mr Ellis told the BBC: "It got to that point I knew that I was in a situation that I didn't want to be in, and I didn't know how to get out of it."

Duggan died in 2004. But the programme uncovered allegations about another Australian monk who moved to Fort Augustus shortly after Duggan.

Father Chrysostom Alexander, now 77, repeatedly sexually abused Fort Augustus pupil Brendan (not his real name) in 1977.

Brendan told me he felt sick after the first assault and then Fr Chrysostom swore and told him to get out.

"I thought, 'what have I done wrong? I did what you wanted'," Brendan said.

Media playback is unsupported on your device Media caption Fr "Chrysostom" Alexander refused to comment when approached by the BBC

Brendan said Fr Chrysostom told him not to tell anyone what had happened, but he did tell his parents, who complained to the school.

However, the headmaster, Father Francis Davidson, failed to alert police to the allegation. Instead, Chrysostom was sent back to Australia - again - with no warnings about his offending.

Father Davidson declined to be interviewed but in a statement said: "In behalf of the former monastic community and of the school of Fort Augustus Abbey, I wish to offer the most sincere and profound apology to the victim and his family for any abuse committed by Father Chrysostom Alexander."

Fr Chrysostom joined Aidan Duggan in Sydney, and became a parish priest. While in Sydney, the BBC tracked him down and confronted him.

Media playback is unsupported on your device Media caption The Abbot President of the Benedictines apologises to victims of child at Fort Augustus school

He refused to answer the allegations. During the course of the BBC investigation, the Catholic Church in Sydney stripped him of his priestly faculties pending an investigation. Police Scotland is also investigating a number of complaints relating to monks at Fort Augustus.

The BBC interviewed , Dom Richard Yeo, the Abbot President of English Benedictine Congregation, which unites autonomous Roman Catholic Benedictine communities of monks and nuns.

Dom Richard Yeo said: "I want to say that I'm very sorry about any abuse that may have been committed at Fort Augustus.

"The big problem with Fort Augustus, [is] that the school closed 20 years ago. The monastery closed, what, 15 years ago, and a lot of the people involved are dead. Under those circumstances it's going to be very difficult to get answers which are going to satisfy people."

The programme also contains allegations that the abbey was used as a "dumping ground" for problem clergy who had confessed to abusing children.

Image caption Downside Abbey monk, Richard White was jailed for five years in 2012

Richard White, who was a Benedictine monk at Downside Abbey in Somerset, confessed his abuse to his abbot more than 20 years ago. He was sent to Fort Augustus in 1993, instead of being handed to police.

His victim, Rob Hastings, told the BBC the allegations had been covered-up and he had been moved out of Downside school.

Mr Hastings said: "The sole response to the situation was to move me, for him to be moved, for there to be very little knowledge of what happened and for life to carry on as normal.

"No police, no reporting, no authorities, no nothing. No psychiatrists, no conversation, no nothing."

Last year, Richard White was sentenced to five years for abusing two boys at Downside in the late 1980s.

Abbot President Yeo admitted he knew White had been sent to Fort Augustus, rather than handed to police.

He said: "It was a mistake that it wasn't reported to the police. It was wrong. I know that.

"In a monastery he would have what I think you call, 'a circle of support'. People who would keep an eye on him, and give him the support he would need to avoid offending.

"I wouldn't say [the victims] get cast aside, they just get forgotten about, that's the danger. I'm not saying it's good and I'm very sorry that it was like that."

Image caption Fr Paul Moore was also sent to Fort Augustus after confessing to child abuse

Former Prestwick priest Fr Paul Moore was also sent to Fort Augustus in 1997, after he confessed to child abuse dating back to 1979.

Both he and Richard White featured in a photograph from the Abbot's Jubilee celebrations in 1997, alongside prominent figures in the Scottish Catholic Church including The Most Reverend Mario Conti, the then Bishop of Aberdeen, and The Right Reverend Hugh Gilbert, who was then the Abbot of Pluscarden.

The BBC asked both clerics whether they were aware of the allegations made against Fr Moore, when the photograph was taken.

In a statement, Bishop Gilbert, now Bishop of Aberdeen, said "Father Paul Moore was not known to me" while Archbishop Conti, now Archbishop of Glasgow, said he only "became aware of the allegations … when they appeared in the national media".

However, the picture was taken on 30 September 1997, two weeks after the story appeared in the newspapers on 16 September.

When the BBC again asked Archbishop Conti and Bishop Gilbert whether they knew that Fr Moore was a child abuser, neither was available for further comment.

Image caption White and Fr Moore were sent to the abbey. White is seen on the left side, and Fr Moore is on the right

Father Moore confessed to abusing children to the then Bishop of Galloway, Maurice Taylor, who failed to alert the authorities for eight months.

The priest's victim, speaking for the first time, told the BBC how Fr Moore abused him at an Ayrshire beach.

Tony, not his real name, is a former altar boy. He said: "[The priest] was somebody you looked up to, you trusted, you believed in. And you would not think they would do any wrong."

Fr Moore was never charged. He told the BBC he regretted if anyone believed his actions had been abusive, and that that had never been his intention.

Fr Moore is still listed as a retired priest and lives in house purchased with church money for his use.

Bishop Taylor declined to be interviewed, but in a statement said: "The initial advice I was given was that since no allegations had been made against Fr Moore but that he had made personal admission to me, I didn't need to inform the authorities."

BBC Scotland Investigates: Sins of Our Fathers is available on the BBC iPlayer