Andrew Hellen (46) claimed not to have been responsible for accessing video clips by computer, two of which showed underage teenagers subjected to sex with adults and another featured a child aged nine or 10 posing in make-up and a lingerie-style top.

At Preston Crown Court, Judge Edward Slinger said the material was "deeply disturbing".

Hellen, of Ada Street, Burnley, denied three charges of making indecent photos of children. He was jailed for 17 weeks and told he would be on the Sex Offenders' Register for seven years. Hellen was also made subject of a sexual offence prevention order for five years. He is barred from downloading anything from the Internet, save for lawful employment or study. He is also barred from taking employment, paid or otherwise, that would bring him into contact with anyone under 16.

Miss Louise Whaites (prosecuting) said computer records showed an attempt to access other material of that nature. Hellen was a man of previous good character and written testimonials were handed to the court on his behalf.

Mr Roderick Priestly (defending) said the case involved a small number of images, downloaded over a short time span, which the defendant had not shown to other people or had distributed.

Mr Priestly added: "He continues to deny the matters. The offences occurred at a time of great emotional upheaval."

Hellen had served in the Armed Forces in the past and the proceedings had had a salutary and extensive effect on the defendant.

Judge Slinger told Hellen: "You know that people who become involved at any stage with such material can expect immediate custodial sentences, if only as a way of attempting, through the message going out, to protect these young vulnerable girls.

"You are clearly a man who has been respected in his employment and in your social musical activities, a man who has always worked hard, who has never previously been before the courts. But there is clearly another darker side to your character, of which your referees knew nothing, that which emerged before the jury.

"You have thrown away your good character and will no doubt have to live with this shame for many years."