text: In a series of Freedom of Information requests, BBC Scotland asked how many cases, concerns and complaints of child exploitation, and child sexual exploitation were recorded in the past four years.
  But the force said the figures were not held on a single system.
  Scotland's Children's Commissioner said the revelation was "disturbing".
  It comes on the day that officers launched a new unit to help with what police acknowledge is the complex problem of child abuse and neglect across Scotland.
  It will provide expertise to allow local teams to robustly investigate cases, including child sexual exploitation, online offences and other types of abuse.
  In its response to the BBC's FOI requests, Police Scotland said: "Child exploitation covers a broad range of criminal activity and doesn't correlate to a specific offence, but rather can involve a range of differing offences...The level of data you have requested is not held on a single system."
  It comes after the publication last summer of the Jay report into sexual exploitation in Rotherham in South Yorkshire.
  It revealed that more than 1,400 children were subjected to appalling sexual abuse.
  Last year Glasgow City Council said 97 children in the city were victims, or at risk of, sexual exploitation.
  The Association of Chief Police Officers said most forces in England and Wales now put a marker on such offences in their records, but senior officers here say that it is not easy to do.
  Children's Commissioner Tam Baillie said: "I am disturbed that we do not yet collect police figures on children who are the subject of sexual exploitation.
  "This was a recommendation of the Scottish Parliament and features in the Scottish government action plan on child sexual exploitation.
  "The reason this is so important is that unless we know the scope of the problem we are trying to deal with, then we won't have the appropriate or proportionate response."
  Assistant Chief Constable Malcolm Graham, from Police Scotland, said the nature of child sexual exploitation made it highly unlikely that young people would come forward to report being abused.
  "Our priority is to be focussing on identifying as many victims as we can and identifying perpetrators who have the intent to commit these devastating crimes so we can prevent the abuse from happening," he said.
  "Scotland is at the forefront of approaches to child sexual exploitation.
  "Sexual exploitation is a form of abuse and it is not a specific crime type recorded as such. Children and young people may be victim of repeated rapes, physical assaults or grooming offences and we categorise all of these in crime recording."
  He added: "But what is most important here is our focus on identifying who these victims are.
  "Our focus is always on where there are child protection issues, and on keeping children safe."
  Martin Crewe, director of Barnardo's Scotland, said: "Rotherham was a real wake-up call and led to the Scottish government's national action plan last year but we could and should be doing more.
  "Our concern is that we don't know the full extent of the problem. We welcome the work of the police.
  "Since the publication of the Barnardo's Scotland petition in 2011 we have been pushing for a better understanding of child sexual exploitation in Scotland."
  In January 2013, Aileen Campbell, Minister for Children and Young People, responded to the Public Petitions Committee inquiry into Child Sexual Exploitation in Scotland, and announced four points including, action "to improve the way child sexual exploitation is identified by Scotland's new single police force to make this form of abuse more visible".
  However, sexual exploitation per se is still not recorded or centrally collated.
  The Scottish government said figures are available on the wider problem of child abuse.
  A spokeswoman said: "The safety of our children is a key priority for the government and an issue we take extremely seriously.
  "The launch of the National Child Abuse Investigation Unit will help to target and bring to justice those who seek to harm our young people.
  "The unit has been set up to tackle all forms of child abuse, and child sexual exploitation is one aspect of this. We have robust legislation in place to cover a wide range of these offences, including online abuse and are working to strengthen the law even further."
  She added: "The extent of the problem is often difficult to assess because abuse by its very nature is concealed. That's why prevention and swift action to safeguard children are a big part of our strategy to tackle these terrible crimes.
  "This includes robust National Child Protection guidance, action to tackle emerging forms of child abuse including child sexual exploitation, a national public awareness campaign and guidance for night-time workers such as taxi drivers and hotel staff who may come into contact with those at risk."
target: Police Scotland has said that it does not collate or hold specific figures on child sexual exploitation.