Gareth Reilly, a 46-year-old man from Newport, has been sentenced to 20 years in prison for raping a girl four times over a protracted period, starting when she was five years old.

Reilly appeared at Newport Crown Court where he was found guilty following a trial. He denied the offences but showed no remorse for the crimes which began in the early 2000s.

Judge Richard Williams described Reilly's actions as an "entrenched pattern of serious sex offending against a particularly vulnerable child."

"You are 46 and have not otherwise been in trouble. You maintain your innocence and there is no remorse to be taken into consideration," the judge told Reilly. "The probation service has found you pose a low risk of further offending in general but a high risk of a further sexual offence against a child."

Reilly's barrister, Byron Broadstock, told the court that there is no suggestion his client had targeted any other children. "He's a man of, until these convictions, good character. He was in employment and had been for many years. The effect [of the case] on his children and his parents has been profound... He knows he is facing a very significant sentence but beyond what I have said – given that he has been found guilty by a jury – there is little I can say."

Judge Williams declared that Reilly poses a "significant" risk of causing serious harm to girls and has shown "little prospect" of rehabilitation. He classified Reilly as a dangerous offender and handed him an extended sentence of 20 years in prison followed by four years on licence.

Reilly must serve two-thirds of the prison term in custody before he can be considered for parole and will be on the sex offenders' register indefinitely.

A hearing to decide a restraining order and sexual harm prevention order will take place on February 24.