The Crown Prosecution Service (CPS) could and should have extradited a paedophile music teacher suspected of grooming and sexually abusing a string of girls at a school in Manchester, the independent inquiry into child sexual abuse has heard.

In 1990, detectives began investigating Chris Ling, a violin teacher at Chetham’s School of Music. He had moved to the US with some sixth form pupils – one of whom he married – promising to make them classical music stars.

Shortly after moved, one of his students had told her parents that Ling had abused her at Chetham’s, prompting a police investigation. Twelve girls were interviewed, a number of whom made similar complaints about sexual touching, sexualised behaviours and sexual assaults, Fiona Scolding QC, counsel to the inquiry, said on Monday.

The school knew this but the support provided to the girls then and now was “non-existent”, the inquiry was told.

Ling was never extradited to stand trial and the complainants were told it was due to a lack of evidence. The truth, according to a lawyer representing a number of the former pupils abused by Ling, was that the CPS had made a mistake.

“In 1990, when the criminal prosecution of Christopher Ling was aborted, our clients were told that the prosecution had failed for lack of evidence. It was only when reading the material supplied in this inquiry that they learnt that in fact the prosecution was aborted because of legal errors by the Crown Prosecution Service, who wrongly decided that Ling could not be extradited,” Richard Scorer from Slater and Gordon told the inquiry.

“As a result, our clients have had to live for 29 years with the belief that their own evidence was of little value and was insufficient to merit a prosecution. That has been doubly wounding, and my clients have asked me to put on record their disappointment and frustration that they were misled in this way.”

The women did their best to move on, but in 2013, they read that another Chetham’s violinist, Frances Andrade, killed herself after giving evidence against her abuser, the head of music at Chetham’s, Michael Brewer. He was eventually jailed for six years after being found guilty of sexually assaulting her when she was 14.

Six women came forward to the Guardian to talk about how Ling groomed and abused them. This led to a police investigation known as Operation Kiso, which eventually saw the CPS agree to apply to extradite Ling to face 77 charges against 11 women when they were aged between nine and 15.

But Ling shot himself at his home in Los Angeles on 1 September 2015 when police knocked on the door to arrest him and take him to the airport for his extradition.

Scorer said Chetham’s put its own reputation above the welfare of children at the school, including five of Ling’s victims.

“At Chetham’s, our clients did not feel safe or nurtured,” he said. “They experienced a highly sexualised and twisted culture in which pupils were coerced and manipulated into sex with adults.

“Far from being able to trust the adults who were supposed to be protecting them, some of them found that their housemother was in thrall to their abuser and that the school’s external reputation was always more important than the welfare of its pupils.”

The inquiry heard that the school had made no proactive approaches to Ling’s victims.

“The support provided by the school since the Ling scandal broke in 1990 has been non-existent. There has been no attempt to reach out to pupils and former pupils affected by abuse; no helpline number to call; no offer of support of any kind; and no attempt to ask for the advice of survivors about what will help to prevent the abuse or help recovery from it afterwards,” said Scorer.

In a statement, the school said: “It is a matter of deep and profound regret to Chetham’s that former teachers at our school betrayed and manipulated the trust that had been placed in them in order to harm children for which we are truly sorry.”

The school insisted it had overhauled its safeguarding practices but apologised that “it did not do more to provide emotional support to the victims and survivors of abuse and their families”.

The former pupils were concerned that Chetham’s had not learned from their suffering, said Scorer: “Our clients remain concerned that while there may have been a procedural shift in dealing with safeguarding, there may not have been a cultural shift. Many of the staff at Chetham’s now were also there when this abuse took place. Old attitudes die hard, and so we urge you to be cautious in accepting assurances about the extent of change.”

Some of Ling’s victims are due to give evidence to the inquiry on Tuesday.