The father of an autistic teenage girl who killed herself at boarding school after telling her GP she was suicidal has told how he would wander the streets 'for hours' in grief after finding out she was dead.

Caitlyn Scott-Lee, 16, who had anxiety and depression, was found dead the night before she was due to serve a two-hour detention, but despite asking her doctor for help she was classified as 'low risk' and given an appointment in six weeks time.

Her father Jonathan was informed of his daughter's death by the headteacher of the £44,000-a-year Wycombe Abbey School, Jo Duncan, and immediately went to London to try and be close to her.

The banking technology executive told the Telegraph: 'Just after Caitlyn died, I went straight to London and spent some time there. I had a day or so where I was just lost – you don't know what to do after your daughter has died.

'So I just start walking the streets of London, I was literally walking the streets of London aimlessly not knowing where to go and I stumble into Piccadilly Arcade.'

Caitlyn Scott-Lee, 16, took her own life at Wycombe Abbey the night before she was set to sit for a two-hour detention

Caitlyn was autistic and had become fixated on the 'headmistress' detention', which had been given to her after vodka and a tattoo kit was found in her music locker

While lost in grief, he came across a signet ring shop where he was gifted a ring he still treasures, containing strands of his daughter's hair, after telling the shopkeeper about his loss.

Caitlyn had become fixated on the 'headmistress' detention', which had been given to her after vodka and a tattoo kit were found in her music locker.

The 16-year-old had been so distraught that she ran away from a choral performance at Eton College where she was due to sing shortly before the Easter holidays on March 21.

Writing in her diary shortly before she died, Caitlyn said running away had been a 'cry for help', adding 'safeguarding my arse'.

Mr Scott-Lee is now campaigning to raise awareness around autism and suicide prevention.

Autistic people are nine times more likely to kill themselves than people who are not autistic, research shows.

Her father previously said: 'It never occurred to me that I should have asked whether my daughter would - very literally - leave school alive.'

He told the Times that Caitlyn had made an appointment for herself at a High Wycombe GP for her 'anxiety, depression and having suicidal feelings'.

She attended the appointment on March 30 and was referred to Buckinghamshire's child and adolescent mental health services.

Then, four days later, on April 3, she was deemed 'low risk' following a phone consultation with the mental health nurse. A specialist appointment was made for her for almost six weeks time on May 16.

She killed herself on April 21.

Jonathan Scott-Lee told The Times: 'I want Caitlyn's story to lead to change, so that neurodiverse children get the help needed in schools and medical settings [and] also thrive in society.

'If she had been prioritised appropriately and obtained medical intervention, she might still be with us.'

Caitlyn's father has now started a campaign for all autistic children who disclose suicidal or depressive feelings to be seen by a specialist within 24 hours.

Caitlyn's father has now started a campaign for all autistic children who disclose suicidal or depressive feelings to be seen by a specialist within 24 hours

Professor Sir Simon Baron-Cohen, director of Cambridge University's autism research centre, said the 'low risk' assessment and delay in receiving NHS specialist help was 'shocking and wrong'.

'The combination of being autistic and depressed makes that child high risk,' Baron-Cohen said.

'We need a rapid response pathway when an autistic child [reports] suicidal feelings - and everyone involved, including teachers and doctors, should be a part of that rapid response. If you are trying to prevent a death, you can't hang around.'

Baron-Cohen also called on boarding schools - like Wycombe Abbey where Caitlyn attended - to make autistic people their highest priority due to their increased risks.

Caitlyn's father said he now hopes to publish his daughter's diary in the hope it will help others and give an insight into understanding how she was feeling.

The diary was retuned to them by the coroner ahead of an inquest. The family said the diary shows she was struggling with sleep as she appears to have written in it between 3am and 4am.

Wycombe Abbey is a £44,000-a-year private school. Established in 1896, the school has around 650 female pupils aged 11 to 18 and each girl has her own 'House Mother', a girl in the year above in the same house who looks after her, especially in her early days at the school.

Wycombe Abbey is a £44,000-a-year private school. Established in 1896, the school has around 650 female pupils aged 11 to 18

After Caitlyn's death, her school said safeguarding was its 'highest priority and the wellbeing and happiness of each and every one of our pupils lies at the heart of everything we do here.

'We are well aware of the crucial importance of effective pastoral support for the young people in our care and our pupils know that staff are always available to listen to them and support them.'

It added its pupils all have access to in-house counsellors, a chaplain, and an on-site health and wellbeing centre. The school added that it was in close contact with family still and that their continued thoughts are with them at this time.

Likewise, a spokesperson for Oxford Health NHS Foundation Trust said: 'We were saddened to hear of the death of Caitlyn and are in touch with her family, the police, and the coroner to ensure we assist fully with the ongoing investigation.

'While that process is taking place we cannot provide further information, other than to send our deepest condolences to Caitlyn's parents, wider family, friends and all those who loved her.'

A full inquest into her death is set to be held on September 14.

For help and support, call the Samaritans for free from a UK phone, completely anonymously, on 116 123 or got to samaritans.org.