Edinburgh Academy has apologised for "brutal and unrestrained" historical abuse that allegedly occurred at the private school.
A total of 20 teaching staff were subject to allegations, including a child being beaten with a cricket bat, another pupil suffering a "small bleed on the brain", a child being strangled, and boys being paid to swim naked.
During the Scottish Child Abuse Inquiry, nearly 50 witnesses gave evidence, including BBC broadcaster Nicky Campbell, who attended the fee-paying school, between 1966 and 1978, from aged five to 17.
Edinburgh Academy admitted "serious sexual abuse was widespread".
It said it expressed regret that police were not brought in to deal with former teacher, Iain Wares, who was described by a lawyer for survivors as "one of the most prolific abusers in Scottish criminal history".
Instead of being reported to police, Wares was allowed to keep teaching and moved to Fettes College.
The college, also in Edinburgh, issued an apology for allowing Wares to keep working despite allegations because of the intervention of a psychiatrist.
He was finally dismissed in 1979 and returned to South Africa.
"The school is truly sorry and this is a full and unreserved apology for the abuse while at Fettes," spokesperson Graeme Watson said.
Wares and fellow teacher Hamish Dawson, who died in 2009, were publicly named during the inquiry - which took closing submissions on Wednesday. Wares faces 74 charges.
Academy 'failed its pupils in terrible ways'
Alan McLean KC, representing the Edinburgh Academy Survivors group, told the hearing nine former pupils had taken their own lives.
He described how pupils were subject to "disproportionate, sadistic corporal punishment", and violence and homophobic bullying was also common among pupils.
"Edinburgh Academy failed its pupils in terrible ways," he said.
"Pupil on pupil sexual abuse took place."
Calum McNeill KC, representing Edinburgh Academy, said the physical abuse that occurred was "brutal" and "unrestrained" while "serious sexual abuse was widespread and continued undetected".
Although corporal punishment was legal in private schools until 2000, Mr McNeill said: "It is clear that beatings took place which were not punishment."
He said: "The atmosphere of fear and constant vigilance against injustice is something the school is deeply ashamed [of]."
'Significant efforts' to bring perpetrator to trial
Following the allegations against Wares, efforts are in place to extradite him to Scotland to face charges.
Lord Advocate Dorothy Bain KC, said she is aware of the frustration at the length of time this has taken, putting delays down to the COVID pandemic.
"In 2020 we were told that the extradition had been ordered but that the accused's surrender would be delayed due to pandemic travel restrictions. We were later told that he had exercised his right to appeal," she said.
"Appeal procedure in South Africa is different in timescale and approach to here."
Police Scotland have also launched an investigation into the allegations.
The inquiry, before Lady Smith, continues.