Father who killed his daughter, 3, with an 'immense' blow to the stomach and failed to call for help jailed for seven years Richard Green, 23, fatally punched ,Lia, as he resented looking after her Was seething with contempt for Lia's mother, Natalie Critchley for an affair Critchley also jailed for 21 months after failing to seek help for daughter At one point they lied and said their daughter had fallen off a swing A judge said intervention would have 'almost certainly' saved her life Richard Green who lost his temper and killed his three-year-old daughter with an 'immense' blow to the stomach has been jailed for seven years A father who lost his temper and hit his three- year- old daughter with such force that it perforated her bowel and killed her, has been jailed for seven years. Richard Green, 23, lashed out in anger and 'delivered an immense blow' to the stomach of his child, Lia, as he resented looking after her on his own, a court heard He was also seething with contempt towards his partner, Lia's mother, Natalie Critchley, 21, whom he correctly suspected was having an affair at the time. Critchley was herself jailed for 21 months today after she failed to seek prompt medical help for Lia which would have 'almost certainly' saved her life, Preston Crown Court heard. Lia was taken to hospital on August 30 last year from the family home in Norris Street, Preston. She was later pronounced dead and a post-mortem examination found that part of her bowel had been severed by the force of the blow inflicted on her. Sentencing Green, Mr Justice MacDuff said: 'You lost all control. You hit, or perhaps kicked, Lia so violently that you caused the perforation of her duodenum. The force required to do that is immense. He added to his 'wickedness' by then not calling an ambulance in the hours that followed, said the judge. Critchley also failed to seek help when she realised Lia was hurt and joined him in covering up the injuries through 'mistaken loyalty' to try to protect Green rather than her daughter. The judge told Critchley: 'You did play roulette with her life. You did not want to have to explain how she came to suffer her dreadful injuries and you hoped she would recover. Green pleaded guilty in April to manslaughter during his murder trial, while Critchley was convicted of child cruelty by the jury. The trial heard that Critchley had begun seeing another man, the parent of a child at the nursery where she worked as a nurse. She was later pronounced dead and a post-mortem examination found that part of her bowel had been severed by the force of the blow inflicted on her She has also been jailed for child cruelty after failing to seek help which would have saved her daughter's life She lied to Green, claiming to be at pole-dancing lessons, to carry on the affair but he discovered what was going on in the weeks before Lia was killed. After an ambulance was eventually called, the defendants 'jointly concocted a series of breathtaking lies to save your own skins', said the judge. One such story they told detectives was that Lia had fallen off a swing. Anthony Cross QC, defending Green, said: 'I suppose it is not a surprise that at some stage this young father would use violence to his own child because, sadly, he was himself the victim of extensive abuse as a child which led to him being taken into care.' Neil Flewitt QC, for Critchley, said his client's conviction 'does not diminish the grief she feels towards the loss of that child'. Oxheys Recreation Ground in Preston, Lancashire. The couple 'jointly concocted a series of breathtaking lies' including that Lia had fallen off a swing in the park to 'save their own skins' a judge said Floral tributes outside the little girl's address in Preston, Lancashire Both defendants will serve half their sentences in custody - less time spent on remand - and the remainder on licence. Following sentencing, Detective Superintendent Andy Murphy said: 'The sentences reflect the severity of the crimes committed but no punishment served will ever bring little Lia back. Both Richard Green and Natalie Critchley will have time to reflect on their actions, actions that led to the death of their own child. This was a complex and difficult case to investigate and we were determined to get to the bottom of what happened. I would like to express my thanks to the Crown Prosecution Service for their work on the case and today the thoughts of the investigation team are with Lia.