Police in Leicestershire have paid out almost £100,000 to registered informants in exchange for details on criminals over the past two years, it has emerged.
The informants, which can include convicted offenders and prison inmates, have helped Leicestershire Police officers gather evidence against organised crime gangs as well as low-level criminals in order to make arrests.
Those who have committed no crimes have also passed on information they have picked up through personal or professional knowledge of criminals.
The force would not reveal how many people it currently has on its register of informants or give details of any cases – citing its duty to protect them from reprisals.
In 2015/16, the amount paid to informants was £23,438. In 2016/17, the amount paid was £73,397.
In recent years, the level of payments reach almost £100,000.
The force stressed the system was rigorously monitored and the small number of detectives who are allowed to deal with informants were supervised at all times and all payments recorded.
A former officer who had extensive involvement in the handling of informants previously told the Leicester Mercury: "This is probably the most regulated area that we deal with. It’s a really difficult and delicate game.
"But, if you get it right, it's massively rewarding for us in terms of the time it can save on investigative resources.
"Officers always have to bear in mind that an informant might be giving them information for bad reasons – maybe they have a vendetta with another criminal or want to remove the opposition.
"The skill is knowing how to handle them and the information they give."
Superintendent Mick Graham, of Leicestershire Police, said: "All use of informants is risk assessed, managed and quality assured at three separate levels to ensure compliance with the law.
"All contact with informants and the information they pass is recorded on a dedicated system that is checked and quality assured by specialist staff.
"There is a robust system in place to manage and record payments to informants and this was subjected to a successful independent compliance audit last year.
"There is an annual inspection to make sure that our use of informants complies with the law."