WILTSHIRE Police pays secret informants thousands of pounds every year for information to crack serious crime, the Adver can reveal.

Data released under the Freedom of Information Act shows the force has paid covert human intelligence sources, known as CHIS, a total of £244,935 in the last seven financial years, ranging from £18,386.90 in 2005/6 to £45,874.25 in 2008/9 and £40,883.42 last year.

Wiltshire Police say they are value for money and have proven highly effective in protecting the public.

But despite the cost to the public purse, the force has refused to reveal anything more for fear of identifying the assets, including how many are on its books, the range an informant can be paid, or what sort of people they are, for example, whether they include turned gang members or private investigators.

The practice is so secretive that even the force policy document on CHIS is restricted and has yet to be redacted as a public facing document, but the force says if it were redacted, nothing would be readable apart from the title page.

Temporary Det Supt Willie Glasgow, the director of intelligence at Wiltshire Police, said: "In an ideal world people would come forward and provide us with information in the form of a witness statement which we could use to bring offenders to justice.

“Unfortunately, it is not an ideal world and many people do not want to provide information to the police. Finance is a motivation so we do, on occasion, pay for information.

“We have a duty of care to provide a level of protection to people that provide information and that is in general as opposed to just in relation to informants. In each case we need to balance the risk against the witness/informant and whether the impact of using that information/intelligence is greater than if we did not use it.

“Informants have proved to be a highly effective method of tackling crime, recovering stolen property, proceeds of crime, drugs, firearms and other prohibited articles.

“I am satisfied that their use has prevented serious harm to the public whether that be through apprehension of a offender and has prevented further offences or it has allowed intervention opportunities to prevent crime happening. I am satisfied that it is worth the money and beneficial to the prevention and detection of crime in Wiltshire.”

He said the force had methods of assessing and grading intelligence to determine its accuracy and credibility, as well as mechanisms for dealing with people who lie, adding that intelligence which is not used does not receive payment and not all information acted upon results in payment.

Angus Macpherson, Wiltshire’s new police and crime commissioner, said he wanted to read the secret policy and find out about the context of the payments.

“It could be one person having got £240,000 or it could be 240,000 people having £1,” he said. “So without that knowledge and the outcomes it’s hard to say whether it’s good value or not. ”

Swindon South MP Robert Buckland said paying informants was one of many useful tools in tackling crime, but stressed that payment should only be made after information has led to a detection of crime.

He said: “That principle should apply when it comes to providing information and intelligence, otherwise you end up with the situation where people are just giving any old information just to get a bit of money.”