Image copyright Oli Scarff Image caption Food Standards Scotland said most of the problems were in Indian-style lamb dishes

About 8% of meat tested in Scotland in 2017 was found to contain the DNA of an animal not listed on the labelling, figures obtained by the BBC suggest.

The National Farmers' Union Scotland said that in some cases the data showed "clear examples of food fraud".

Processed foods such as Indian-style lamb dishes, kebabs and sausages were among the dishes found to be at fault.

In a number of cases, pizza toppings that were supposed to be ham were identified as chicken or turkey.

Image copyright Jeff J Mitchell Image caption Pizza toppings were found not to be as advertised

Information collected by Food Standards Scotland (FSS) showed that 631 tests were carried out last year.

It said 48 of them were "contaminated" with the meat of animal that either was not on the label or menu description.

The samples, tested randomly, were taken from restaurants, supermarkets and manufacturers.

The FSS would not reveal the names of the premises or even the type of business they operated.

On the face of it the figures suggest the rate of contamination in Scotland is not as high as in the rest of the UK where tests in 2017 found that as much as a fifth of meat samples had been misrepresented in this way.

Image copyright Kristian Buus Image caption Information collected by Food Standards Scotland showed that 631 tests were carried out last year

However, the FSS warned that the data could not be directly compared as England, Wales and Northern Ireland did not compile the information in quite the same way.

The differences could also be caused by more targeted inspections of certain food industry sectors likely to have standards or safety issues.

A freedom of information request by the BBC's Good Morning Scotland programme to FSS showed various "contaminations" across the country.

They include:

Barbecue pork spare ribs tested from a "primary producer" in Falkirk were found to be chicken

A lamb passanda from a restaurant in Dundee was found to contain peanuts when it shouldn't have, and it consisted of beef. No lamb at all was detected.

Also from a restaurant in Dundee a product described as "cooked lamb" was found to contain no lamb at all - only beef

Several pork sausages from manufacturers and retailers in Stirling were found to contain pork and beef - at higher levels than could be explained through cross-contamination

A Greek chicken stir fry from a shop on the Western Isles was found to contain both turkey and chicken

A meal from a restaurant in Angus described as "beef in oyster sauce" was found to consist only of pork

Scotch beef mince from a shop in Edinburgh was found to contain beef and pork and "would be objectionable to consumers wishing to avoid pork for cultural reasons". This sample was also found to contain genes associated with e.coli however inspectors believed they would have been "killed through the normal cooking process, but have the potential for cross-contamination of other foods until cooked".

Minced lamb from a shop in Glasgow contained both lamb and chicken.

Image caption The DNA is tested in a number of Scottish laboratories

The random tests are carried out on behalf of Scottish local authorities by four specialist laboratories.

The Glasgow Scientific Services Lab run by Gary Walker tests samples for 16 councils.

Anything above 1% is considered contamination.

Image caption Gary Walker runs the Glasgow Scientific Services Lab

He said: "There can be a very small amount of one meat in the presence of another and it's simply that a piece of machinery hasn't been cleaned properly, so that's not malicious it's just one of those things.

"But we have also seen other things which are a bit more deliberate, where one meat has been substituted for another."

He said cost and availability were two main factors why people might be doing this.

What type of foods are most frequently susceptible to this?

Image caption Dr Jacqui McElhiney said most of the problems were in Indian-style lamb dishes

Dr Jacqui McElhiney, head of food protection science and surveillance at FSS, said most of the problems were in Indian-style lamb dishes.

She said: "We also saw issues with lamb kebabs, where the expectation was that the kebab was 100% lamb.

"And also, maybe more interestingly, pizza toppings that were supposed to be ham, but were actually identified as chicken or turkey."

She also said the number of contaminations were roughly in line with the figures for 2015 and 2016.

Dr McElhiney urged anyone in the food industry in Scotland who had concerns to report them on the Scottish Food Crime Hotline on 0800 028 7926 or to use the online form on Food Standards Scotland's website.

Image caption Alan Clarke, of Quality Meat Scotland, said Scotland had been a pioneer in quality assurance

Alan Clarke, of Quality Meat Scotland, said Scotland had been a pioneer in quality assurance right through the supply chain.

But he admitted that one case of contaminated meat was "one case too many".

He said: "When you drill down into the figures, yes, there are some examples of genuine error, but there are some which have been unscrupulous operators.

"If you're an unscrupulous operator and you do something outside the law - you will be caught."

Horsemeat scandal

NFU Scotland's livestock policy manager John Armour said part of the solution might come about through introducing better country-of-origin labelling.

He said: "We have constantly been pushing for country-of-origin labelling on processed products.

"At the moment, it only exists on fresh cuts of meat, so we would like to see sausages and curries for example in supermarkets with country-of-origin labelling."

Mr Armour said the horsemeat scandal of 2013, where products were found in the UK containing horse DNA, showed the meat was actually coming from other parts of Europe.

He said: "If people knew that, for example the sausages and other processed-meat products they were buying, contained only British and Scottish beef and lamb, pork or chicken, then they can be more confident that it is the real deal."

A Scottish government spokesman said: "Consumers have every right to expect that what's on the label is what's on their plate.

"We expect local authorities to take appropriate action where necessary to protect food standards and safety."

Dr McElhiney, from the FSS, added: "We would urge anyone working within the food industry in Scotland who has suspicions or knowledge about food fraud or food crime to report them on the free and confidential Scottish Food Crime Hotline on 0800 028 7926 or using the online form at Food Standards Scotland's website."