POLICE Scotland is wrongly recording "several hundred thousand" stop-searches a year.

The national force has come under increasing political scrutiny over what its own numbers have made look like a tactic of mass frisking, including of children.

However, its chief constable, Sir Stephen House, has now admitted that vast numbers of routine encounters, such as taking alcohol from youngsters, had skewed official statistics.

Speaking before his main civilian watchdog, the Scottish Police Authority or SPA, on Friday Sir Stephen took personal responsible for "some mistakes in data gathering and presentation".

The chief constable had been summoned before the SPA after the BBC reported figures that appeared to show the force breaching its own policy - announced last summer - of not carrying out consensual searches on under-12s were also wrong.

The broadcaster had said there had been 356 such suspicionless searches since the change in policy.

It had obtained the numbers under Freedom of Information laws.

The force had not wanted to release them, telling the broadcaster they thought the numbers were corrupted.

The body representing rank-and-file officers has long argued that Scottish statistics for stop-and-search were being inflated - and that resulting meaningless figures were sparking political controversy.

The SPA on Friday was told the latest analysis suggested that the actual number of under-12s subjected to consensual searches was 18.

Most were youngsters stopped by police after youth disorders before their ages could be checked.

Sir Stephen said "I don't think we should routinely be using consensual search on children. But it is a policy, not a law,. if my officers step outside the police and they have got a good reason, they will get 100% support."

He said that if so-called "interventions" - for example, when officers remove alcohol from children - were removed from figures there would be dramatic reduction in the wholesale number. Such "booze blitzes" are routine in Glasgow, where stop and search figures are highest.

Sir Stephen said official numbers "would reduce by several hundred thousand" without such mass confiscations, which have widespread public support.

The representing rank-and-file officers has for some years warned that stop-search figures have been inflated by what it regards as a "targets culture".

A spokesman Scottish Police Federation or SPF said the SPA meeting at which Sir Stephen was speaking could be "best summarised by saying 'the numbers are guff'".

The force, meanwhile, has said it believes that consensual searches should be reviewed. One of Sir Stephen's deputies, Rose Fitzpatrick, said many consensual searches were nominally made for alcohol. There is no statutory power to frisk for such drinks. Police believe such a power should be considered.