A vigilante group, which trapped a paedophile by posting a photograph of a child on a social website, may have committed an offence.

Now a judge has ordered a probe into whose picture was used and where the group, calling themselves The Children’s Guardians, obtained the image of the alleged 14 year old.

The vigilante gang tricked Gary Armstrong, 39, from New Romney into believing he was talking with two school children.

But, Canterbury Crown Court, has heard the children didn’t exist and Armstrong – known on the internet as “Romney Guy” – was actually communicating with adults from the group.

Armstrong, of no fixed address, was lured to a sea front rendezvous before being confronted.

But Judge Simon James said he was concerned about the delay in the police being alerted which could have put at risk other children.

He cut Armstrong’s jail sentence because there had been no victims.

He added: “This is a most troubling case even though he was actively targeting and sexually grooming children.

“There is an element of disquiet about how these offences have come to light because those involved in organisations, such as the Guardians, may consider their activities have been justified by the guilty pleas.

“But I have to confess to having considerable reservations concerning the way this particular organisation has acted.”

The judge said he was concerned how Children’s Guardians had uploaded a child’s image to the internet before bringing matters to the attention of the police.

“The delay in reporting of these matters had the real capacity of putting other children at risk and the rule of law must take precedence in a civilised society.”

He added that any intent to get around that cannot be encouraged “no matter how well intended “

In giving Armstrong a seven year extended jail sentence, the judge said he believed he had been entrapped by the group.

Armstrong, who has already served a previous jail sentence for sex offences involving real children, was told he would be given a five year custodial sentence and the judge added two more years which he will have to serve on licence when he is released.

Judge James said Armstrong had a “warped sexual interest in children” and ruled he posed a danger to the public.

“The delay in reporting of these matters had the real capacity of putting other children at risk and the rule of law must take precedence in a civilised society...” - Judge Simon James

He also ordered the Crown Prosecution Service to conduct an enquiry in to who’s image was used by the group and called Steph and whether or not the law had been broken by the group.

Armstrong , who admitted using the group Little Mix to try to groom the fake child, is now subject to a five year Sexual Harm Prevention Order, restricting his use of the Internet.

He had admitted six sex offences involving fake young teenagers called Steph and Katie after being lured to the sea front and confronted by the group.

An NSPCC spokesman said: “Despite a previous sentence for similar offences Armstrong’s disturbing behaviour remains and his intentions in this case are further evidence of the risk he poses to children.

“To help protect young people in the digital world, social media companies need to act.

"That’s why the NSPCC’s Wild West Web campaign is calling on government to make sure new safety laws for social networks are not only fit for purpose, but are also backed by an independent regulator.”