Sussex Police warned against relying on vigilantes after Shadow Hunters UK helped snare Ian Collard.

Collard, 28, of George William Mews, Portslade, was arrested at the park on Victoria Road after the vigilantes arranged to meet him there through an online decoy as reported in The Argus.

A girl's mother had asked them to help after her 13-year-old daughter had been contacted by him on Facebook.

ASussex Police spokesman said: “At about 11.30am on Sunday (June 3), police arrested a man at Victoria Road Recreation Ground in Portslade following information received from members of the public.

“We rely upon the assistance of the public in preventing and detecting crime. Working with the community is a vital factor in our gaining information.”

When asked to comment on the involvement of Shadow Hunters UK in this incident, the spokesman said: “Cases involving child sex abuse are extremely serious and have a huge impact not just on the victims, but on whole families and the communities in which they take place.

“So-called paedophile hunters are taking risks they don’t understand and can undermine police investigations. Most importantly, unlike our officers, they have no way of safeguarding child victims.

“Our approach to these groups has not changed. We may work with these groups in certain instances, if it helps us protect children and we can manage the risks of their involvement.”

In the statement, Sussex Police raised other concerns. The spokesman said: “Revealing the identity of suspected paedophiles gives the suspect the opportunity to destroy evidence before the police can investigate them.

“It can also lead to people who have been identified going missing or raising other concerns for their safety. This can divert significant resources to the task of protecting suspects, which would be better invested in investigating and, where the evidence justifies it, prosecuting them.”

They urge anyone who has concerns about online grooming or similar to contact police via or call 101. If you think a child or young person is at immediate risk of harm, dial 999.