Michael Colebourn outside Winchester Crown Court on March 11

A heartbroken father today said 'I desperately miss being a daddy' as his estranged wife was jailed for life for murdering their 'beautiful' three-year-old daughter by drowning her in the bath.

Former science teacher Claire Colebourn was handed a life sentence at Winchester Crown Court with a minimum term of 18 years after being convicted of murdering her daughter Bethan.

Sentencing her, a judge said that on the night of the young girl's murder, 'The person from whom Bethan needed to be protected was her own mother.'

The court heard Colebourn hit 'rock bottom' after her high-flying husband Michael, a chief executive at luxury marine interior company Trimline, ended their 16-year relationship.

She woke their daughter at their home in Fordingbridge, Hampshire, in the early hours of October 19 2017, led her to the bath and held her body under the water before making multiple suicide attempts.

Colebourn had sobbed in the dock as the prosecutor listed websites such as 'How to kill by suicide', 'What is the least painful way to commit suicide?', and 'Lost all hope' which she had accessed.

The ex-sixth form biology teacher was discovered by her mother about 14 hours later in a diabetic coma.

After the sentencing, Mr Colebourn said his 'beautiful daughter' had been taken from him in a 'cold and callous manner at the very hands of the one other person that should have protected her and kept her safe'.

In a statement, he said: 'The one thing in my life that gave me purpose has gone.

'I desperately miss being a daddy - we would have such great times together; Bethan's laugh was infectious and her energy was endless.

'There is not a second in the day that goes by that I am not thinking about her.

'Bethan was my world and being her daddy made me so proud. I miss her so much.'

Bethan was discovered dead in a downstairs bedroom in the family home having been drowned around 14 hours earlier

'The one thing in my life that gave me purpose has gone': Shattering statement given by father after his wife was sentenced for murder There are no words to describe the past 18 months. The one thing in my life that gave me purpose has gone. My beautiful daughter has been taken from me in such a cold and callous manner at the very hands of the one other person that should have protected her and kept her safe. The loss of Bethan has had a huge impact on so many people: family, friends, and all that knew her. She was such a special little girl – bringing so much joy to all their lives. Throughout the criminal trial, I and all those that loved Bethan have had to endure the heartbreak of listening to her last moments. I have also had to suffer endless unfounded allegations and lies made against me with no opportunity to respond. I desperately miss being a daddy – we would have such great times together; Bethan's laugh was infectious and her energy was endless. There is not a second in the day that goes by that I am not thinking about her. Bethan was my world and being her daddy made me so proud. I miss her so much. Advertisement

Colebourn, dressed in a black jacket and wearing glasses, rubbed her temples with her hands, shook her head and looked at the floor as details of her crimes were given to the court.

The 36-year-old did not react when handed the sentence.

Mrs Justice Johannah Cutts said: 'She [Bethan] was clearly a beautiful little girl who was full of life. She had everything to live for.

'You were her mother, you were responsible for her care and her well-being.'

Colebourn planned to end Bethan's life, set an alarm to 'carry out the act' and altered her will the next day.

During the eight-day trial, the jury of five women and six men were told she initially denied all memory of the incident, but later recalled how Bethan agreed to have a bath in the middle of the night at her mother's instruction, telling police: 'Sadly, my little girl trusted me completely.'

Colebourn admitted killing Bethan but said she only wanted to 'save' and 'protect' her from her father - who Colebourn had met at university.

The pair separated just over a month before Bethan's death and Mr Colebourn had moved out.

Claire Colebourn (police mugshot pictured) killed her daughter Bethan at their home in Fordingbridge, Hampshire

Kerry Maylin, prosecuting, told the court their relationship had been difficult and the defendant had made 'unfounded accusations' her husband was having an affair with his company's finance director, claiming the pair were planning to take over the business and start a new life together.

Colebourn went looking for her husband's car and became convinced he was monitoring her computer so bought a new one and changed her internet connection.

Within minutes of receiving the new computer in October, she started searching for suicide-related websites, the court heard.

A doctor described how she was 'only emotional when discussing the fact Michael Colebourn had left her and her daughter and her father had done the same to her mother'.

In a letter intercepted at hospital, she said: 'In my eyes I saved her, everything over those days is a blur.'

Colebourn later told police: 'I am responsible for Bethan's death because she drowned and I am responsible for it.

'Bethan drowned because I was there, I held her under the water.'

Ms Maylin said Bethan was particularly vulnerable given her age and had trusted her mother.

Mrs Justice Cutts said Mr Colebourn was 'in no way responsible' for Bethan's death.

Police officers at the scene of the murder in Hampshire in October 2017

Paramedics and police officers attempted to perform CPR on the youngster but they were unable to save her

Karim Khalil QC, defending, said Colebourn appeared to have a personality disorder but this was disputed among experts.

He said a doctor assessing Colebourn at a mental health facility in Oxford said she 'appeared to have a personality disorder' and was 'emotionally unstable'.

Victim impact statements from Bethan's family were not read in court but were read privately by the judge before today's hearing.

The court heard she has already spent 327 days in custody, which will be deducted from the 18 year sentence.

An NSPCC spokesperson said: 'This is a desperately sad case in which a young child lost her life in the most tragic of circumstances.

'Bethan would have looked to her mother for love and protection. Sadly, Colebourn failed her daughter in the worst possible way.

We all have a responsibility to protect children. Adults can report their concerns to the NSPCC helpline on 0808 800 5000 or dial 999 if a child is in immediate danger.'