The body of violin teacher Frances Andrade, 48, was found at her home less than a week after she gave evidence against Michael Brewer, 68, at Manchester Crown Court.
The revelation came after the prosecution case closed and the former director of music at the internationally-renowned Chetham’s School of Music was defending himself against a number of sexual allegations.
Brewer’s ex-wife Kay, 68, was also accused of indecently assaulting Mrs Andrade, then known as Shorney, and aiding and abetting rape.
The Crown Prosecution Service decided to continue with the trial and the judge ruled that news of Mrs Andrade’s death should be kept from jurors until after they reached their verdicts today.
The jury of six men and five women found Brewer guilty of sexually abusing the victim in his office at Chetham’s, in Manchester, when she was 14 and 15. Mrs Brewer was also convicted of indecently assaulting the same victim when she was an adult at their then family home.
Brewer was cleared of raping the victim when she was 18 and Mrs Brewer was cleared of aiding and abetting rape. Brewer was also cleared of indecently assaulting the victim as a child in his home.
Brewer was cleared of raping Mrs Andrade when she was 18 at his then home in Chorlton, Manchester.
He was convicted of five counts of indecently assaulting her at the age of 14 and 15 when she was known as Frances Shorney.
Kay Brewer, 68, of Knowl Gap Avenue, Rossendale, Lancashire, was cleared of aiding and abetting the alleged rape but convicted of one count of indecent assault against the complainant - said to have taken place on the same night as the alleged rape.
Mrs Andrade was visibly agitated on occasions as she gave her evidence over two days on January 16 and 17.
She chose to give evidence in the witness box in full view of everyone in the courtroom, including the two defendants in the dock.
The jury heard that the police investigation was sparked by National Youth Choir teacher Jenavora Williams after her friend, Mrs Andrade, told her about her time at Chetham’s.
Mrs Andrade told the court she wanted it to be dealt with internally but she said Mrs Williams went to the police in 2011 without telling her.
She then co-operated with the police and agreed to take part in the prosecution.
The mother-of-four, from Guildford, Surrey, who was married to acclaimed viola player Levine Andrade, was supported from the public gallery by one of her sons.
At one point she complained about Brewer smiling as she gave her evidence, but she chose to press on without drawing a curtain to block off the dock.
Judge Martin Rudland remarked that she was “clearly undergoing a cathartic experience, whatever the source” while giving evidence.
He said she was “combative” during cross-examination by Kate Blackwell QC, representing Brewer, and she had taken personal issue with some of the barrister’s questions but the judge indicated that Miss Blackwell had acted professionally.
During the cross-examination, Mrs Andrade told Miss Blackwell: “You are hugely insulting, even though it’s your job.”
On January 24 it was revealed in court - while the jury was not there - that the complainant had died and it was believed she had killed herself.
A day earlier, the jury - on the direction of the judge - recorded not guilty verdicts on five counts of indecent assault against Brewer due to insufficient evidence about how old the complainant was at the time of the allegations.
Judge Rudland put a temporary reporting ban on the tragic development and kept it from the jury, which was told that matters had arisen which required a brief adjournment.
Brewer then continued to give his evidence before his ex-wife went into the witness box.
Brewer, who was awarded an OBE for services to music in 1995, resigned as music director at Chetham’s at the end of 1994 after his affair with another pupil, then aged 17, was uncovered.
But the affair was hushed up, the court heard, and, after leaving Chetham’s, Brewer went on to become the artistic director of the National Youth Choirs of Britain, to direct the World Youth Choir, serve as an adjudicator in international competitions and lead BBC workshops for the programme Last Choir Standing in 2008.
One of his ensembles at the National Youth Choir gave a private performance to the Queen at Balmoral in 2007.
Judge Martin Rudland told the defendants that a jail sentence for both of them was “inevitable” as he remanded the pair in custody.
He told them he would need pre-sentence reports to determine the length of custody on a sentencing date to be fixed.
Both will also have to sign the sex offenders register.
Sending the jury out, the judge told the court: “Tragically a lady has lost her life during the course of these proceedings.
“She took her own life. She left no note. We do not know the circumstances of which she took her own life.”