A karate expert who sexually abused pupils, including during a lesson on fighting off sex attackers, has been jailed for 10 years.
Henry Cook, known as Harry, also had more than 55,000 child porn images and 600 videos on his computer.
He abused five girls in his class, one as young as 11, in what the judge at Newcastle Crown Court described as "the most appalling catalogue of sexual depravity" which spanned 26 years.
Cook, 62, of Haltwhistle, Northumberland, who has written a critically-acclaimed book on the martial art, even abused one of his young victims during a lesson on how to tackle sex attackers.
He befriended his victims, groomed them with gifts of perfume, books and skimpy clothes, then sexually abused them in the loft of his home, in his mother's house, in abandoned buildings and in a dojo - a Japanese-style martial arts gym - in his back garden. Many of the incidents took place while his wife and family, who have now disowned him, were at home.
After Cook was jailed, one of his victims said in a statement: "After living with the immense horror for over 20 years I feel some justification and I'm relieved that people can now see him for what he truly is.
"He is the lowest form of predator taking advantage of young and vulnerable girls and abusing his position of trust. I feel total disgust and loathing towards him for all he has done and he is now where he belongs. I hope he remains in prison for a very long time."
Det Con Gillian Allen, of Northumbria Police, said: "We commend the victims and their families as well as Cook's family for the way in which they have conducted themselves throughout this difficult period. We hope that this sentence can help them achieve a certain amount of closure."
Following the hearing, Cook's family said they had the utmost respect and sympathy for his victims. In a statement they said: "The whole family have been deeply distressed by what has come to light over the past months and would like to make it known that we utterly condemn his actions, and have totally renounced him.
"We applaud the courage of those victims who have come forward, and we would like to thank all those people and organisations who have offered us help and supported us throughout these very difficult times. We are eternally grateful for their goodness and humanity."