OFFICIAL figures showing that crime is at a 40-year low have been questioned following fresh allegations of Police Scotland manipulating the statistics.

Police insiders have told this newspaper that the single force is deliberately keeping the figures low by marking crimes as "incidents" and handing out verbal warnings.

It has also been claimed that officers persuade victims against pursuing complaints by informing them they will have to give evidence in court.

The Scottish Government last year announced that the recorded crime figures, which are based on Police Scotland data, fell to their lowest level since 1974.

However, several sources close to the force, speaking on condition of anonymity, say the claim cannot be trusted due to the figures being fiddled.

In 2013/14, 273,053 crimes were recorded north of the border, but over 2 million "incidents" were logged with the police.

The force insiders told the Sunday Herald that various methods are used to stop incidents from spiralling into a crime report, which has the advantage of reducing paperwork and not adding to the recorded crime total.

One way is simply to ensure that some low-level crimes are left as "incidents" and effectively left off the books.

In other cases, such as for anti social behaviour, assaults, and minor traffic violations, officers use their "discretionary powers" to stop the incidents from being upgraded to a recorded crime.

One police source added: "Police officers can also talk victims out of pursuing their complaint after explaining that they will have to be a witness in court. That can put off a lot of people. It happens all the time."

Even in domestic abuse cases, an area highlighted as a priority by single force chief constable Stephen House, the distinction between incidents and recorded crime is huge.

In the last financial year, 58,976 domestic abuse incidents were logged, but only 56.7% resulted in a crime report.

In a crime audit covering 2012/13, Her Majesty's Inspectorate of Constabulary (HMICS) found that 13% of all so-called non-crime incidents had not been closed correctly.

Some incidents failed the HMICS test as a "crime had clearly been committed but no crime report was traced", while in some other cases the "complainer became uncooperative".

Renfrewshire and Inverclyde had the lowest compliance rate for processing incidents correctly ( 83%), with Ayrshire coming second bottom at 86%.

The inspectors noted in their report: "Scrutiny of incidents reported to the police is a weakness in most divisions."

Another way the figures can be nudged down, according to the police insiders, is when a recorded crime is retrospectively nullified, otherwise known as "no-criming".

HMICS found a 94% compliance rate in all "no-criming" cases, but revealed a 14% failure rate in Argyll and West Dunbartonshire and 17% in Renfrewshire and Inverclyde.

Some of the decisions were judged to be incorrect, the inspectors concluded, due to a "lack of additional credible information to dispel criminality".

The report added: "In a few cases, officers appeared too ready to disbelieve the complainer. In some divisions, the explanation for why a no-crime decision was made was poor."

A combination of these practices, the sources say, deflates the recorded crime figure and allows Police Scotland and the Scottish Government to trumpet the success of their justice policies.

Scottish Conservative justice spokeswoman Margaret Mitchell MSP said:

"This latest revelation confirms the fears and reservations previously aired about the so-called 40 year low crime stats.

"Worse still it shows how some crimes and offences are merely being recorded as incidents and how the public is being discouraged from reporting and pressing their complaint."

Scottish Liberal Democrat justice spokesperson Alison McInnes MSP said:

"Police Scotland risks hemorrhaging public confidence if it cannot once and for all demonstrate credibility in their recording practices. With fresh questions now hanging over the accuracy of the number of recorded crimes, people will want the Scottish Police Authority to ask searching questions of the police chief."

Labour justice spokesman Hugh Henry said: "If it's true that recorded crime figures are being manipulated for political ends then it would be a major scandal and Michael Matheson, the Cabinet Secretary for Justice, would have questions to answer. Audit Scotland should be asked to investigate the accuracy of recorded crime statistics as a matter of urgency."

A spokesperson for the force said: "In November 2014, HMICS stated that the quality of most incident and crime recording decisions in Police Scotland is good. Officers will use their powers of discretion when appropriate and proportionate, this includes when dealing with instances of anti-social behaviour and minor road traffic violation.

"Police Scotland has a victim centred approach which serves the needs of all victims of crime. It is simply not correct to suggest that officers would suggest a victim does not continue with their reported crime."