TV presenter and chart-topping classical pianist James Rhodes has described in detail being raped as a six-year-old at a prestigious London prep school.

The author laid bare the extent of the abuse he suffered in the serialisation of a memoir so contentious it became the subject an injunction banning its author from even being named,

The extract was published yesterday (SUN) in a newspaper, days after the Supreme Court had ruled in favour of Rhodes and his publishers, Edinburgh-based Canongate.

In it, the 40-year-old describes being showered with presents and affection as he was groomed by a PE teacher, Peter Lee, his "aggressive rape" by Lee in a locked gym closet, how the trauma turned him into "a mini-psychopath" addicted to drugs and alcohol who was later detained in a secure mental unit - and how his life was saved by classical music, in particular Bach's Chaconne for solo violin.

In the hard-hitting memoir, to be published later this week, Rhodes writes: "Abuse is when you tell a traffic warden to f*** off. It isn't abuse when a 40-year-old man forces himself into a six-year-old boy. That doesn't even come close to abuse. That is aggressive rape."

He says that "literally overnight" he went from being a "dancing, spinning, gigglingly alive kid who was enjoying the safety and adventure of a new school to a walled-off, cement-shoed, lights-out automaton. It was immediate and shocking, like happily walking down a sunny path and suddenly having a trapdoor open up and dump you into a freezing cold lake."

Rhodes also mentions the surgeries he required in later life as a result of the repeated rapes, and lists the mental and physical ills which befell him, among them depression, self-harm, drug addiction, gender confusion, "vigorous" self-harm, paranoia, eating disorders and what he calls "suicidal ideation".

When his classical music career began to take off after the release of his first album in 2009, Rhodes mentioned the abuse in an interview, prompting a former staff member to contact him. She told him she knew some kind of abuse was happening at the school and recalled that she used to find Rhodes "sobbing, blood on my legs, begging not to go back to gym class." It was her statement to police which resulted in Lee, then in his 70s, being tracked down to Margate, where he was still working with young boys. He was arrested and charged with 10 counts of buggery and indecent assault but after a stroke was deemed unfit for trial. He died shortly afterwards.

The sexual assaults took place at Arnold House School in upmarket St John's Wood, London, a feeder school for Eton, Westminster and Harrow, where Rhodes went for his secondary education and where a fellow pupil was his friend Benedict Cumberbatch. The Oscar-nominated actor was at Rhodes's side when he learned last Wednesday that the injunction banning his memoir had been lifted by the Supreme Court.

It had been brought in the first place by Rhodes's first wife, who had sought to prevent publication on the grounds that certain passages would prove distressing to their 12-year-old son. In the injunction Rhodes was referred to only as MLA but on Wednesday, in a move hailed as a victory for free speech, the Supreme Court in London ruled that publication could go ahead and that Rhodes could be named as its author.

The book, Instrumental: A Memoir Of Madness, Medication And Music, will be published on Thursday.