, which will be screened on Tuesday on More4.
All three attended Caldicott boys' preparatory school in Buckinghamshire during the 1950s and 1960s. All three were systematically abused by different teachers, including the headteacher.
Tom Perry was 11 years old when the headteacher approached him. "I had a tongue put into my mouth, and I was given a sexual kiss, the first sexual kiss I'd ever had, ever experienced . I can even remember the taste of it, which was grim."
In the quiet, understated documentary, photographs of the three men as prepubescent schoolboys are juxtaposed against their graphic accounts.
"You know when you accidentally break something that you like, like a vase?" Mr Payge tells the camera. "The feeling that I had was that I had to pick myself up, bit by bit, and make myself whole."
Peter Wright, the abusive headteacher of Caldicott, kept his job until 1993. Five victims spoke out against him, and he was charged with 13 counts of sexual abuse and three counts of gross indecency. A court case was eventually stayed because of a legal technicality.
Martin Carson, the science teacher who abused Alastair Rolfe, the third victim, was forced out of Caldicott after his abuse of pupils came to light. He went on to teach for a further 21 years, until he was tracked down in 2001. Carson pleaded guilty to multiple charges, some of which now carry a maximum sentence of life. He was jailed for two years, and served 12 months.
Mark Payge's abuser was never charged.
Figures from the NSPCC show that three in 20 children in Britain experience sexual abuse. And boys' preparatory schools, the documentary suggests, are a haven for paedophiles. Unlike state schools, private schools were until recently under no obligation to report staff who abused pupils. As a result, few did: potential damage to the school's reputation was considered irreparable.
"If you're a paedophile, why wouldn't you go and work at a prep school?" said Mr Rolfe. "It's the obvious place."
But a spokeswoman from the Independent Schools Council insists that this is not the case. "Independent schools are no different in this respect to maintained schools," she said. "Schools are subject to rigorous child- welfare legislation, regulation and inspection, which is entirely right and proper. The interests of the child are at the heart of an independent education."
To accompany the programme, Channel 4 has produced four questions which parents should pose to independent-school heads. One is about the school's child-protection policy, another on the training staff receive in child protection.
Such measures, the programme-makers hope, will prevent future generations from having to live with the legacy of abuse that has haunted the three men.
"Keep busy, keep busy," Mr Perry tells the camera. "If you're busy, you have less time to think. But there's an emotional tsunami behind you . if it catches up with you, you know you're going to be in trouble."