The guidelines - drawn up by a group from agencies working with vulnerable children - describe running away as a “teenage phenomenon” and a Scotland-wide problem, with one in nine Scots children involved by the age of 16. The true extent of child prostitution is likely to be hidden “behind closed doors,” the group states. Both sets of behaviours were often “closely associated with difficulties at school such as bullying, truancy and getting into trouble”.

Parents may not inform the agencies of any problems. It was vital therefore that the professionals who come in contact with young people were “aware of the need to pick up changes in the child’s behaviour which may indicate he or she is at risk”.

As well as identifying children at risk, and playing a role in inter-agency action to help individual pupils, schools are urged to include discussions about problems in family life. Packages on sexual exploitation, for example, could be “a helpful way of exploring difficult issues with children and young people in a non-stigmatising way. It is important that teachers are provided with suitable materials to allow them to discuss these issues and to deal with any problems which may arise”.

Douglas Hamilton, research and policy officer for Barnardo’s Scotland, said: “The availability of suitable materials is crucial but, given that a high number of children run away or consider running away and that we do not know the true extent of child prostitution, it would be helpful to make this a whole-class issue.” A recommendation by the charity that research be undertaken to determine the extent of the problem is included in the guidelines.

Euan Robson, the Deputy Minister for Education and Young People, told a launch event for the guidelines in Glasgow that they aim to protect the most vulnerable young people. He added: “Prostitution is a hidden shame.

Unless we know its extent it is impossible to tackle effectively.”