NEW YORK (CBSNewYork/AP) – A new investigation into alleged sexual abuse at an elite New York City private school has found that the abuse was more widespread than previously reported.

The investigation into the Horace Mann School identifies 63 former students who say they were abused from the 1960s through the 1990s.

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“In my view it was, for long periods of time, a nest of pedophiles,” said report co-Author Leslie Crocker Snyder.

The ongoing abuse remained secret until after the highly publicized scandal at Penn State University, which inspired Horace Mann victims to break their silence.

“We all knew there were certain teachers who had a reputation for being a little more hands on with students,” said Horace Mann graduate Josh Gelman. “A little more personal with students than most were comfortable with.”

The report was compiled by The Horace Mann Action Coalition, a nonprofit group founded by alumni to address the scandal. They say abusers included coaches and teachers of both sexes, a dean, heads of departments, a headmaster and a head of guidance.

“I know of two cases where students were being abused by one teacher and were summonsed to see the chair of the guidance department and the chair of the guidance department proceeded to sexually violate them in that meeting,” said a witness who did not want to be identified.

Web Extra: Read the complete report (.pdf)

The number of alleged victims is more than double the 25 cited in a 2013 report by the Bronx district attorney’s office.

“About four decades; over 60 some-odd young, mostly boys, but a few girls, were victimized and they had no redress,” Snyder said. “This is a life-long traumatic crime and it was treated without any real concern by this school.”

Among the report’s recommendations are a change in New York state law extending the statute of limitations for sexual abuse. All of the incidents contained in the report happened too long ago to be criminally prosecuted.

The report does not allege a cover-up conspiracy at the school but rather implies a web of denial, CBS2’s Lou Young reports.

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Peter Brooks, who is part of the group that paid for the investigation, said Horace Mann officials declined to cooperate, WCBS 880’s Peter Haskell reported.

“The entire stance of the school sends the message that says ‘we don’t want to know, don’t come forward, don’t speak up,'” he said.

The student body is largely composed of gifted children of the rich, and sometimes famous, who often felt like their children were being groomed for greatness, Young reported. Tuition at the elite school cost $43,300 for most students during the 2014-2015 academic year.

In the decades since there have been suicides, drug addictions, and lately — since the statute of limitation has run out — cash settlements with the victims. But the effort to keep things quiet has never relented.

Critics say Horace Mann has always been focused on it’s image to the exclusion of everything else.

“The problem is that some of its best teachers were allowed to flourish as pedophiles,” Snyder said.

The school said in a statement Tuesday it would review the report to determine whether it contains any suggestions that would further strengthen child safety.

It also has a child abuse section on its website, inviting former students to contact the administration with any concerns about physical treatment they may have experienced.

CBS2’s inquiries to the school were referred to the headmaster’s office where the person who answered the phone said “no comment.”

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