Greater Manchester Police have paid more than half a million pounds to informants over the last five years.
Some critics have labelled it as an “ineffective use of money” while others argue it is “cost-effective”.
Informants are used by the police to find out information on criminal activity such as murder, burglaries and drug rings.
Journalism students from the University of Portsmouth submitted Freedom of Information requests to all English forces asking them to state how much has been paid to informants during each of the last financial years.
GMP’s total for 2014/15 to 2108/19 came to £558,883, with £136,260 handed over during the most recent year.
Neil Wood, a former undercover policeman, said in his experience about “90 per cent of informants are used in drug-related offences”.
Mr Wood, who is now chief executive officer of Law Enforcement Action Partnership, rallying for drug reform policy, said: “Using police informants for other crimes such as burglaries and theft is the most cost-effective form of policing you can do.”
But he also points out that what informants are mostly used for does not reduce the crime in the area.
“If you arrest a drug dealer on the information of an informant, you remove a drug dealer.
“All it does is create an opportunity for another drug dealer; crime doesn’t reduce,” Mr Wood added.
Informants, he said, can be paid anything between £20 and £15,000 for sharing information leading to successful arrests.
A senior officer in the biggest spending Met Police, who wished to remain anonymous, said: “If the information from an informant leads to the recovery of firearms or incarceration of serious criminals this can only be a positive thing, even if the informant receives financial benefits.”
A spokesperson from Taxpayers’ Alliance said: “It is critical that there is transparency in how taxpayers’ money is spent, even in the murky world of crime-fighting.
“All bodies, including the police, ought to be aware of the public interest in knowing where their cash is being spent, especially given that taxpayers are being asked to pay record amounts this year.”
Reader Candace Moss said: “Morally, I don’t think we should be paying anyone to give us information.
“If you witness a car crash and give a witness statement, you don’t expect to receive money for it.’