A British Transport Police (BTP) officer created the wanted-style poster, which contains mugshots of 30 children known to authorities in the West Sussex area, to aid with “safeguarding and crime prevention”.

It comes as we launch an investigation into a spate of youth crime near railway stations on the Worthing line, from Goring to Hove.

The poster was hung up in a Southern Rail office, where pictures of it were taken and passed on, including to The Argus. We have blacked out 28 of the faces as their identities are protected by law.

A poster made by a British Transport Police officer for Southern Rail staff. It has 30 children known to police, including George Tilley, left, and Archie Tilley, right, who have been sent to prison for 12 years after beating Alan Willson at a Worthing park last year (Image: Argus)

BTP referred itself to the Information Commissioner’s Office (ICO) after admitting that it was “inappropriate” to hand the posters to rail workers.

A spokeswoman for BTP said: “We can confirm an internal investigation has been launched in relation to a document which shows a number of juveniles known to police in the West Sussex area.

“This was created by an officer and provided to the local train operating company to aid safeguarding and crime prevention efforts. It was then subsequently copied and shared.

“We have acknowledged this was inappropriate and referred ourselves to the Information Commissioner’s Office.

“Our own enquiries continue alongside our railway partners to establish the full circumstances of what happened.”

The ICO has given advice to the force about data protection and taken no further action.

An ICO spokeswoman said: “British Transport Police made us aware of an incident.

“After carefully reviewing the information provided, we gave data protection advice and recommendations to British Transport Police and closed the case with no further action.”

A Southern Rail spokeswoman said: “We are working with the British Transport Police to support the enquiries into this matter.”

George Tilley, left, and brother Archie at a previous court appearance. They can be revealed after reporting restrictions were lifted in July

The poster includes George Tilley, 15, and his brother Archie, 16, who shattered the skull of 47-year-old Alan Willson, leaving him with permanent brain damage after beating him with logs last year in Longcroft Park, Worthing.

The two boys were crossed out and “12 years” written underneath their pictures, the sentences they were handed in July.

The other children, 14 girls and 14 boys, cannot be revealed due to reporting restrictions set out under Section 49 of the Children and Young Persons Act 1933.

The act places an automatic restriction on reporting information that identifies or is likely to identify any person under 18 who is concerned in youth court proceedings as a victim, witness or defendant.

The reason for this as stated by the Crown Prosecution Service is that “public identification of children and young people is irreversible and can cause both immediate and long term distress and harm”.