A former police informant who claimed Avon and Somerset Police failed to protect him said he has been threatened with being “chopped up”.
He said he was identified by criminals and has subsequently received death threats and attempts to attack him.
The man claimed the force used him inappropriately as a source of information and did not step in once his identity became known.
Avon and Somerset Police has launched an investigation.
The force said it would “follow the national policing stance and neither confirm nor deny any specific details relating to informants”.
‘I’m going to get killed’
The man, who the BBC is not naming, said he has been targeted repeatedly by criminals since being identified.
“They’ve called me a ‘snitch’, they’ve called me a ‘grass’,” he said. “These are dangerous people, but I’ve had no protection at all.
“I know at some point I’m going to get killed or seriously hurt and I hold Avon and Somerset Police responsible.
“I’ve called them over and over again to protect me. I was told safety measures would be put in place – but they weren’t.
“The kind of weapons these people carry… they’re not there to cut people’s hedges, they’re there to cut people’s heads off.”
The man said he was never formally registered as a police source, though the force said he was registered at one time.
‘We bent the rules’
However, text messages seen by the BBC showed repeated requests for information from him. This would be known as “tasking” and should only be asked of a registered informant. Police have a higher duty of care to registered informants than to other sources of information.
The man has made multiple complaints to the police about his treatment but was still waiting for an outcome.
However, during a meeting with Avon and Somerset Police, a senior officer told him: “There will be lessons to be learned about managing an individual like you… without breaching the legislation… it looks like we bent the rules because it was a unique situation.”
Avon and Somerset Police would not confirm or deny any details of the case, but said: “The use of informants to assist in investigations is a resource used by law enforcement agencies across the country.
“The intelligence provided helps to prevent and solve the most serious of crimes. This is a well-established and highly scrutinised tactic.”