A 48-year-old swimming coach who started having an affair with a 13-year-old girl has been jailed for three and a half years.

Steven Hartley who was also a foster carer for the county council began abusing the child, 31 years his junior, before going on to have full sex with her when she turned 16.

But the married father of three daughters aged 18 to 22 has now jailed after a court heard how he formed a relationship with the youngster, who had become infatuated with him.

Jane Warren, prosecuting, told Swindon crown court that Hartley first met the girl when she was 10 or 11 and he was a coach Warminster and District Amateur Swimming Club.

She said they spent a lot of time together and by the year 2000, when she was aged 13, it must have been obvious to him that she was infatuated with him.

"If it wasn't it would have been when she started to sent sexual text messages to him," she said.

He was suspended from the club after one of his daughters saw a text but rather than distance himself from the child he allowed the relationship to grow, meeting up in secret.

"By the time she was 16 they started to have full consensual sex which continued up until his arrest," she said.

Miss Warren said that Hartley had become so close to the girl's family that when his wife realised he was having an affair she thought it was with his victim's mum.

She said the police became involved after the girl confided in someone who told her parents.

"It was clear to the police that she viewed the relationship as one between equals and found it difficult to see it was abusive," Miss Warren said.

She said he was released on bail after his arrest but remanded in custody after e-mailing her and even when he was in custody he sent her a letter.

At an earlier hearing Hartley, of Hawkeridge Park, Westbury, admitted four counts of indecent assault and one of indecency with a child.

Graham Smith, defending, said that his client served in the Royal Green Jackets for 25 years and was now a broken man.

He said when he is released from custody he will not contact the girl and is full of remorse for what he has done wrong.

Jailing him, Judge Guy Boney QC said: "It is a major tragedy to see a man like you standing in the dock in the crown court surrounded by the wreckage of your life.

"You were a man of 43 and she was 13. You were in a position of responsibility to her and her parents and they were entitled to expect her to be safe in your care.

"You yielded to weakness and you behaved in a way no teacher should to a pupil."

He will also have to register as a sex offender for the rest of his life and will be banned from working with children.

wtimes@newswilts.co.uk