EVIDENCE from vigilantes known as "paedophile hunters" was used to charge suspects on at least 150 occasions last year, it has been reported.

There has been a seven-fold increase in the use of such evidence from 2015, figures obtained by the BBC under Freedom of Information laws suggest.

Two-thirds of the 43 police forces in England and Wales provided data, which also showed that in 2017 almost half of the cases of the offence of meeting a child following sexual grooming used evidence from the groups.

The data only confirmed that the vigilante evidence formed part of the decision to charge a suspect and did not suggest it was the sole reason for criminal action.

The suggested rise in cases that rely on the evidence comes despite police chiefs warning of "significant risks" that arise from paedophile hunters' tactics.

These can include posing as children online to lure in suspects and set up real-world encounters in order to expose them.

Some police fear that the groups' actions could interfere with surveillance operations, while the "evidence" they gather may not be of a high enough standard to use for prosecution.

Among Britain’s most popular groups and organisations is Dark Justice, Guardians Of The North, Silent Justice and Stinson Hunter, but there are believed to be dozens more across the UK.

In March, an inquest heard that a man from Southampton killed himself after he was caught in a sting operation by online paedophile hunters.

And in January a former police chief told the Independent Inquiry into Child Sexual Abuse that masquerading as a child online should become a criminal offence to help snare predators while deterring vigilante paedophile hunters.

Jim Gamble said the crude methods used by have-a-go detectives should instead be taught to a "citizen's army" of volunteers under police guidance.

Despite these doubts this year has seen a number of convictions in North Wales following the intervention of groups determined to bring offenders to justice.

In January an online child groomer from Flint was snared by paedophile hunters when he believed he was chatting to girls aged 12 and 13.

Ricky Martin Bradley asked to meet some of them and suggested they have a relationship but what he did not know was that he was speaking to an on-line decoy for a paedophile hunters group.

Bradley, 27, of Prince of Wales Avenue in Flint, contacted six girls on-line believing them to be aged 12 and 13 but the victims were in fact fictitious after a woman volunteered to act as an online decoy for National Child Protectors, a group which looks for those involved in paedophile activities online. She created false profiles of girls in chat rooms on social media and he had conversations with them of a sexual nature.

Also in January, a Wrexham man was arrested by police following an operation by an internet paedophile hunter group which was broadcast live on the internet.

Michael David Roberts, 31, of Coed Aben in Caia Park, admitted attempting to have a sexual conversation with a child, and attempting to meet a child following sexual grooming.

Roberts exchanged messages with a person he believed to be an underaged girl and arrangements were made to meet.

But it turned out that he was exchanging messages with an online decoy and when arrangements were made to meet he was confronted and arrested with it all being recorded and broadcast on an internet live stream.

Roberts had been in touch with a female, who he believed to be a 14-year-old girl in London, but who was an adult and a member of a paedophile hunter group, Internet Interceptors.

An adult female pretended to be a schoolgirl aged 14 who was contacted by Roberts. She had told Roberts a number of occasions that she was only 14 while in chat room conversations. Nevertheless, Roberts continued to make contract with her believing that to be the case and even made arrangements to meet her in the Wrexham area for the purpose of sexual activity.

During the case, defence solicitor Andy Holliday told magistrates that Roberts' family did not feel it would be safe for him to be in the community and feared a backlash after his arrest was broadcast in a live stream on social media and had soon made its way around the local area.

Successful convictions like these and the role that these vigilante groups are having in conjunction with the police is generating an increasingly public debate about the ethical implications of putting the public in dangerous situations when it comes to the fight against child sex abuse.

Supporters and the groups themselves claim they are a valuable resource exercising their right to fight crime and protect their children but critics say their amateur investigations could potentially tip off paedophiles and give them time to destroy crucial evidence.

Others fear that by publicly “outing” suspected paedophiles, individuals and their families are put at risk of retaliation and punishment despite matters not being heard in a court of law.

Last year paedophile hunters welcomed a court ruling allowing them to continue to pose as children online to catch sexual predators. Legal teams acting for two men who were caught by the organisation Dark Justice allegedly attempting to sexually abuse minors had argued that the use of evidence gathered by such operations “diminished the integrity of the court process” and that the groups should be regulated.

But in a detailed judgment given at Newcastle crown court on Thursday, Mr Justice Langstaff ruled that there was no legal requirement for the activities of Dark Justice to be subject to controls.

The official line from police officers in Wales remains one of caution with North Wales Police warning vigilante paedophile hunters should stop their investigations because they risk tampering with probes into child grooming.

DSupt Gareth Evans said; “ We rely on the assistance of the public in helping prevent and detect crime. We understand the desire to help protect children, however, cases involving child sexual abuse can have a huge impact on the victim, families and the local community , so anyone with information should contact the police so we can support victims whilst investigating and bringing offenders to justice.

“Revealing the identity of suspects in these cases gives them the opportunity to destroy evidence before the police can properly investigate and can raise concerns for the safety of individuals.

“Anyone with concerns should call 101 or email Child Online Exploitation Protection (CEOP) at www.ceop.police.uk. If you think a child is at immediate risk of harm always call 999.”