Former officers have told the Sunday Herald that the statistics are fiddled by the "downgrading" of violent crimes such as serious assault and robbery.
They also said some stop and searches, a policy associated with Police Scotland Chief Constable Stephen House, are simply invented by some frontline officers to boost the figures.
Various authorities south of the Border, including the Metropolitan Police and a House of Commons committee, are probing claims that recorded crime figures are bogus. The UK Statistics Authority said last month that there was evidence the police crime stats in England and Wales were not reliable.
Former officers have said the same problem exists in Scotland. They claim it reflects pressure felt by officers to meet "key performance indicators" and cut the recorded crime figures.
In 2012-13, official figures showed recorded crime down 13% - to the lowest level since 1974 - and non-sexual violent crime falling by a whopping 21%. MacAskill seized on the good news and claimed Scotland's communities were "becoming safer places to live".
These are the final-year figures for the old territorial forces, but the same patterns are evident in the new single force. In December, it was revealed that Police Scotland had reduced violent crime by 13.9%.
However, former officers, speaking on condition of anonymity, have told a very different story about the figures to the Sunday Herald. They say officers feel the need to massage the figures by downgrading crimes. The classification system has two tiers: "crimes", which were down 13% last year; and "offences", which were slightly up. In 2012-13, there were 273,053 recorded crimes, but there were nearly twice as many offences.
The former officers say one way to keep instances of recorded crime low is by reclassifying them. For instance, serious assault - in the same category as attempted murder - is defined as a violent crime whereas, by contrast, "common assault" is only an offence. It fell by 12% last year, but with 60,955 cases is still around 17 times more prevalent than serious assault.
Former officers have claimed some serious assaults are being logged as common assaults. One said this downgrade happens "all the time", while another source said it occurs "loads of times". Another source said the vague definition of "serious assault" was a large part of the problem.
An assault is "serious" if a victim sustains injuries resulting in detention in a hospital as an inpatient, or if there are broken bones, internal injuries, severe concussion or a blow requiring stitches. However, a serious assault does not include a nose being broken, as it is defined as cartilage.
A police source said he knew of a case where a victim's limb was broken, but the incident was recorded as a common assault.
The ex-police officers said the figures were also massaged by recording robberies - another violent crime - as something else. One said: "Robbery is diluted to assault and theft". Another ex-officer confirmed that this particular downgrade goes on, saying: "That is correct."
One former officer said he was aware of an incident where a thief snatched money from a woman in a public place and knocked her to the ground. He said this was a clear-cut robbery, but it was put down as an "assault" and "theft".
In December, the HM Inspectorate of Constabulary for Scotland (HMICS) published its review of incident and crime recording. The report flagged up an issue about the recording of some robberies.
In one sample, inspectors referred to 11 incidents which had been "classified incorrectly". They added: "These incidents were recorded as assaults and thefts but the circumstances described in the record amounted to robbery."
The report continued: "This failure to classify the crime correctly is of concern as, in contrast to robberies, crimes of common assault and theft do not always feature in local performance management information. Such information could therefore result in a misinformed view of serious violent crime in an area."
Separately, the HMICS report found that the majority of officers and staff had not experienced "overt pressure" to change crime recording decisions, but noted: "Some people did however tell us that they were frequently asked to review particular recording decisions (for example, to check whether a particular assault was a common or serious assault). While it is perfectly legitimate for such a review to be requested, some felt these requests amounted to covert pressure and were performance driven."
It added: "Almost everyone said the definition of serious assault was unfit for purpose and required updating. Confusion around the definition may lead to inconsistent practice in recording and counting decisions across Scotland and we therefore recommend that it be reviewed."
The inspectors recommended that Police Scotland, in partnership with the Government, should "review and clarify the definition of serious assault."
If the official figures are to be believed, the old Strathclyde Police force did a great job in reducing violent crime. Between 2007 and 2013, serious assaults were down 53.5% and robberies fell by 50.3%.
The force believed a large part of this drop, which happened on the watch of Chief Constable Stephen House, was due partly to stop and searches, of which 612,110 were recorded in Strathclyde in 2012-13 alone, with a success rate of 13.7%.
One research report claimed the total number of searches in this period was over four times greater than stop and frisk in New York City in 2012.
The policy had two aims: to detect drugs, weapons and stolen goods; and to deter people from carrying these items.
When House took the top job at Police Scotland, the Strathclyde model for reducing violent crime was rolled out nationally.
The single force has a "key performance indicator" for the number of stop-searches and a 15% target success rate. In the first nine months of the single force, 519,213 stop-searches were carried out.
However, former police officers say the number of stop-searches by both Police Scotland and Strathclyde is exaggerated. Due to the pressure officers feel, they say some recorded stop-searches are actually invented.
There are two possible outcomes to a stop-search: either "positive", when action will be taken; or negative, when nothing needs to be done. Although an officer should provide full details of all searches in his notebook, more limited details are required when the information is logged electronically. Fields include ethnicity, gender and age - but not the name and address of the person searched.
Former officers have told the Sunday Herald this has led to officers, who feel under pressure to keep the figures high, making up negative searches.
One way of checking a negative search would be to inspect an officer's notebook, which, this newspaper has been told, would be considered a waste of time.
One former officer said: "The public's perception of the police is enhanced when they read that in their particular area 250 people were stopped and searched."
He said some officers simply "make it up", adding: "An hour before I go off duty I could have recorded 12 fictitious stop-searches. No-one would check. It is very easy to cheat the system."
Asked if this practice occurred, another ex-officer responded: "One hundred per cent right." He added that it was not the fault of the officers, but the result of a culture driven by "targets and key performance indicators".
Another police source said he had heard that stop-and-search figures also include double counting, whereby an officer could record details of a legitimate search for drugs, but then file a separate entry for the same person on the grounds that alcohol was also searched for.
Rose Fitzpatrick, the deputy chief constable of Police Scotland:
"Police Scotland works within the context of an ethical and legal performance framework which is robustly monitored at both command and local level as well as through regular reports to the Scottish Police Authority (SPA), via HMICS inspections and local scrutiny arrangements.
"In relation to stop and search, officers are not set individual targets. However, it is entirely appropriate that Police Scotland works towards performance targets on key priorities, such as violence, which the public tell us are the most important for them.
"There are robust scrutiny arrangements in place at a local and national level so there are a number of forums where any issues or concerns can be raised."