The Crown Prosecution Service in West Yorkshire is forking out on a publicity campaign to try to improve its image.

Criminal justice bosses are concerned about their public perception and believe people often do not know what their role is.

The CPS has taken out a four-page wrap-around advertisement in free newspapers, highlighting its successes and illustrating their work.

Cases featured include the jailing of Yorkshire Ripper hoaxer John Humble, the life imprisonment of the killers of Bradford PC Sharon Beshenivsky and the convictions of four teenagers for the murder of Huddersfield taxi driver Mohammad Parvaiz.

Other articles in the advertisement describe how the CPS decides to prosecute, how anti-social behaviour is tackled and the introduction of witness care units.

West Yorkshire Chief Crown Prosecutor Neil Franklin admitted that public confidence in criminal justice agencies was not as high as it might be.

Mr Franklin said: "The public read stories where people appear to have got off lightly, or should have been held to account but haven't. It only takes a couple of these to hammer public confidence.

"Criminal justice agencies have to raise their game in winning over public confidence. If people aren't confident about criminal justice they are not likely to come forward and make complaints, or stick to the legal process and give evidence at court."

It is the first time West Yorkshire CPS has used such a campaign, which will be followed by advertisements on local radio, and was the brainchild of area business manager Karen Wright, who ran a similar successful promotion when she worked in Durham.

Mr Franklin said West Yorkshire was performing better than most areas but, according to the British Crime Survey, fewer than half of people in the county are confident about criminal justice, although the figure is higher among victims and witnesses.

He said: "I am totally committed to providing the best possible service for the public of West Yorkshire and it is important that our public understand our role. I want the CPS to be visible, transparent and accountable for that part of the criminal justice system for which it is exclusively responsible."

Mr Franklin said he could not put a figure on what the publicity campaign was costing.

But he added: "I do know it represents excellent value for money. If 50 people come forward in the next year to give evidence because they have read the article, it will be worth it.

"We constantly strive to engage our public and this is one of many avenues pursued.

"I hope, as a result of this initiative, that there is greater awareness and understanding of our role and of our commitment to serve the public of West Yorkshire."