THEY are notoriously known the world over as grasses, snitches, squealers, or by their official title of Covert Human Information Sources.

Their details are cloaked in secrecy – as you'd expect as a source of crucial insider information in the fight against organised crime.

Trying to find out how many of them exist and how much each of them earns is nigh on impossible because of fears their identities could be compromised.

But call them what you like, and most do because of the criminally devious "rat on a rat" nature of their actions, because it won't bother them too much.

This is because they are making some serious cash selling their information about co-conspirators to officers.

In Kent alone they are receiving more than £222,000 every year as they tip police off about drug deals, people trafficking and prostitution.

The Courier can reveal in the last nine years Kent Police has spent £2,003,202 on informants – a total of £222,578 each year – or £609.80 per day.

The force refused to say how many "Huggy Bears", the infamous super-grass from 70s TV series Starsky and Hutch, it had on its books or how much the highest and lowest paid grasses in the county were earning.

Surprisingly, the force also refused to discuss its use of informants or answer specific questions on the tactics involved.

Instead it said it backed a statement by the Association of Chief Police Officers which states "informers are a vital weapon in the fight against crime".

Patricia Gallan, ACPO's National Source Working Group chairman, said the use of informants had proved essential in cases ranging from serious organised crime to burglary.

She said: "Each force is audited on their use of informants and is subject to a robust annual inspection.

"They are a valuable source of intelligence and their use is justifiable and proportionate when set against other police tactics."

The use of Covert Human Intelligence Sources is a well-known police tactic in catching criminals who believe they are beyond the long arm of the law.

Forces can pay criminal contacts for information necessary in bringing successful prosecutions and detectives say the confidential deals are vital to cracking tough cases and securing convictions.

But the practice has developed considerably from the Life on Mars style of bunging a source £20 after meeting in a pub.

The payment of money, which comes from the police budget, is strictly governed by the Regulation of Investigatory Powers Act.

The real names, aliases and sums paid to grasses are kept in a register, which can only be seen by a very small number of officers who have been vetted in line with national standards.

Individual officers are banned from having informants.

Instead, sources are closely monitored by specialist informant handling teams tasked with looking after their welfare and assessing the quality and importance of the information they provide.

This information is then used by police as part of their investigations. But it is never treated as evidence and the source is never required to testify in court.

The figures, obtained using Freedom of Information rules, do not include payments made by other agencies such as the security services.

Although £2million in nine years may seem an awful lot of cash to give to grasses, Kent Police does not spent as much as some other forces.

The Metropolitan Police, which covers Greater London, spends that amount every year.