POLICE Scotland and the Scottish Government moved to criticise a new independent think tank report that says the number of crimes cleared up has fallen from 12 per police officer to 8 per police officer in the last seven years.

The new study from Reform Scotland has shown that, despite the hiring of an additional 1,000 extra police officers, "the number of crimes being solved in Scotland is falling".

Whilst acknowledging and welcoming the fact that recorded crime has fallen by 35 percent during the same timeframe, the Thinning Blue Line report says that the number of crimes being cleared-up has fallen from 198,985 in 2006/07 to 139,306 in 2013/14 - a drop of 30%.

It says that is despite the fact that the number of police officers in Scotland has increased from 16,234 in quarter one of 2007 to 17,295 in quarter one of 2015.

Reform Scotland says that means the number of crimes cleared up per full-time police officer has fallen from 12 in 2006/07, to eight in 2013/14.

But Police Scotland have questioned the conclusions and the Scottish Government said the claims made were wrong, saying the clear up rate for all recorded crimes increased by 1% to 52% in 2013-14, the highest recorded since 1976, the first year for which comparable records are available.

Reform Scotland said that clear-up percentage rates were not an accurate measure of success in the number of crimes detected.

A spokesman said: "For example, if in an area there were 100 crimes in year one, with a clear-up rate of 40% and in year two there were 70 crimes, with a clear-up rate of 50%, the actual crimes solved would fall from 40 crimes to 35 crimes."

In November, Scottish Government figures said that the level of recorded crime in Scotland had reached its lowest level in 40 years, falling by 1% in a year.

The think tank added: "Unison (the union) has suggested that police officers are spending more time covering work previously carried out by civilian staff, which Reform Scotland believes could help explain the situation.

"If the pledge to recruit 1,000 extra officers has resulted in police officers having to carry out backroom duties, as opposed to being out on the street, we would question whether it is delivering value for taxpayers' money. As a result Reform Scotland would urge the Government to review this policy.

"Should the Scottish Government remove the pledge, it would not necessarily lead to a reduction in police officers. However it would give greater operational freedom to the police to decide how to best use their own resources, ensuring deployment was an operational, not a political decision."

Police Scotland deputy chief constable Neil Richardson said the report "does not reflect the delivery of modern policing in Scotland in 2015".

He added: "Police Scotland has been focused on keeping people safe during the biggest period of public sector reform and structural change to policing in more than a generation.

"Savings which are the equivalent to the combined budgets of three legacy police forces have been achieved at the same time as performance levels have been maintained and public confidence levels have remained high.

"There has never been more scrutiny of policing in Scotland and our performance is reported regularly in public locally and nationally."

A Scottish Government spokesperson said: "Police officers and staff are doing an excellent job out in our communities keeping people safe from harm and crime in Scotland is currently at a 40 year low. This report fails to recognise the important role of policing, and the 1000 extra officers, in preventing crime, reducing threats and, crucially, providing public reassurance to ensure people feel safer in their communities.

"It also fails to recognise that with a 40 year low in recorded crime reduced crime, supported by increased numbers of officers means, of course, the clear-up rate per officer are going to be lower.