The head of a west London Catholic school has apologised for its "terrible legacy" of sex abuse.
Christopher Cleugh, headmaster of St Benedict's school in Ealing, said the school would adopt the recommendations of an inquiry, led by Lord Carlile.
The report, which looked at 21 attacks since 1970, said Ealing Abbey monks must lose their control of the school.
The abbot has accepted that he "failed" when he allowed a former head facing abuse claims to return in 2007.
The inquiry began last year after Father David Pearce, the former head of the junior school, was jailed for eight years in 2009, after being convicted of abusing five boys over a period of 36 years. Four of the victims were under 14.
The Right Reverend Dom Martin Shipperlee, who was appointed the abbot in 2000, said a victim had complained to him about Father David in 2001 and he had made the police aware of it.
In 2006, a High Court ruling awarded damages to one of Father David's victims. The priest was brought back to the abbey as bursar the following year.
He went on to carry out the final sexual assault in 2007, before being arrested in 2008.
Mr Shipperlee said: "I allowed him to return because I have responsibility to and for him and it was my estimation that the best way I could discharge that was to have him in a place where we knew what he was doing.
"I was wrong. I failed. I didn't get that right at all, so a young person was put in the harm's way."
Later, he told BBC London that the idea of Father David being in the abbey was for him to work solely in the abbey buildings and not in the school or in the parish.
He added: "Clearly, I wasn't monitoring, looking closely enough."
When asked if he was considering his position over the situation, he replied: "I consider my position constantly."
'Conflict of interest'
In the report, Lord Carlile of Berriew said the form of governance at the school was "wholly outdated and demonstrably unacceptable".
"The abbot himself has accepted that it is 'opaque to outsiders'."
Two trusts should be set up to remove "all power from the abbey" while maintaining the Benedictine connection for the parents, Lord Carlile added.
The new governing body must create a clear accountability between school management, governors and trustees.
It should be transparent and understandable to outsiders and deliver effective monitoring, safeguarding policies and procedures.
The new governors must include representatives from the school community and diaspora, as well as people from outside the school, the report said.
It added: "In a school where there has been abuse, mostly - but not exclusively - as a result of the activities of the monastic community, any semblance of a conflict of interest, of lack of independent scrutiny, must be removed."
Following the publication of the report, Mr Cleugh said: "Past abuses at the school have left a terrible legacy for those affected and have tarnished the reputation of St Benedict's.
'Very, very shocking'
"I offer my heartfelt apology for past failures. The school could have, and should have, done more."
"We are determined that safeguarding procedures at St Benedict's should in future be exemplary and the appalling abuses of the past should never happen again," he said.
The recommendations will come into effect from 1 September 2012.
Philip Catterall, whose 11-year-old son currently attends the school, said the findings were "very, very, shocking" but most parents felt "pretty positive" about the recommendations.
He and other parents met with the school's authorities on Tuesday night.
"There were some tough questions for both the head and the abbot - some very hard questions," Mr Catterall said.
But Jonathan West, from Hanwell, the father of a former pupil, said: "The proposals for governance are perfectly sensible but they do not really get to the heart of the problem, which is safeguarding and child protection, not governance."
The Vatican has also ordered a separate inquiry into the historical sex offence allegations.
'Prolongation of abuse'
Keith Porteous Wood, executive director of the National Secular Society which contributed to the report, has asked for a dedicated phone line to be set up to report abuses.
"The absence of such elementary controls and labyrinthine child protection procedures both contributed [to] the prolongation of abuse," he said.
Police are also looking for Father Laurence Soper, 80, former abbot of Ealing Abbey, who failed to answer bail in March following arrest on suspicion of abuse. He taught at the school from 1991 to 2000.
Another former employee faces a trial over sex abuse charges.
Police are looking into new abuse allegations against the school from the 1970s and 80s.
The abbey has run the co-education school for about a century.