A former head teacher at a Yorkshire school has been labelled a manipulative and predatory paedophile and given an extended 12-year prison sentence for a string of sexual offences against boys.

Douglas (Duggie) Speight, 44, pleaded guilty to 15 charges, including sexual activity with a child, causing a child to engage in sexual activity, making indecent images of a child and voyeurism.

Yesterday, the Recorder of Bradford, Judge Richard Mansell QC, set the custodial term of the sentence at 12 years with an eight-year extended licence period.

Speight must serve at least two thirds of the 12 years behind bars and all of it if the Parole Board decides it isn’t safe to release him.

Judge Mansell told Speight, who had been remanded in Leeds Prison: “You were well respected and liked by your colleagues, the pupils and their parents but your public persona hid a very dark secret, in that you are a highly dangerous, predatory, manipulative paedophile with a sexual interest in young boys.”

The offences relate to four boys. Prosecutor Tom Storey said Speight’s eldest victim was changed by the abuse, crying and becoming angry and sad.

He eventually confided in a friend and the police were alerted.

When Speight was arrested he conceded that his behaviour had been inappropriate but denied that anything sexual had taken place.

Police searched his house and found a computer tablet and phones containing indecent videos of the boy taken without his knowledge, hidden behind a picture and an air vent.

Speight then admitted to investigating officers that he had abused the boy.

The boy’s mother told the court that Speight had destroyed her son’s life.

She no longer trusted anyone and was paranoid and terrified for him.

She labelled Speight a “master manipulator.”

The boy’s father said Speight was “an outcast in society.”

He was worried his son would be vulnerable for a long time. Speight had poisoned his view of the world and given his whole family a life sentence.

Julian White said in mitigation that Speight had destroyed his own life and reputation.

He was highly thought of as a head teacher and dedicated and enthusiastic. He was incapable of expressing any rationale to his behaviour.

He was an intelligent and well-educated man of previous good character who had lived in a world of sexual fantasy.

Speight was remorseful and admitted frankly and unequivocally what he had done and the consequences of it, Mr White said.

Judge Mansell said that, after the discovery of the hidden tablet and phones, Speight had little choice but to make admissions, but he played down his offending.

He had also secretly recorded several people, including three boys.

Judge Mansell branded Speight highly dangerous when he passed the extended sentence of imprisonment.

He made an indefinite Sexual Harm Prevention Order and Speight was ordered to sign on the sex offender register for life.