A new Canadian study has found that 20 per cent of sausages sampled from grocery stores across the country contained meats that were not listed on the label.

The study, conducted by researchers at the University of Guelph, examined 100 randomly purchased sausages that were labelled as containing just one ingredient: either beef, pork, turkey or chicken.

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The team examined the sausages using a method called “DNA barcode” testing that revealed one in five of the sausages included some off-label ingredients.

“The vast majority -- 95 per cent of the sausages we tested -- had the species that was on the label in them,” Robert Hanner, the lead author of the study, told CTV News Channel Friday.

“But about 20 per cent had certain amounts of other animals in them. We found that some of the beef sausages contained pork; some of the pork sausages contained beef.”

Of the 100 sausages tested:

7 of 27 beef sausages contained pork

1 of 38 pure pork sausages contained horse meat

2 of 38 pure pork sausages contained beef

4 of 20 chicken sausages contained turkey

1 of 20 chicken sausages had beef

5 of 15 turkey sausages studied contained no turkey at all. They were entirely chicken meat

The researchers were testing only for the DNA of turkey, chicken, pork, beef and horse, so it is not known if the sausages may have contained other meats.

The full results appear in the journal Food Control.

The researchers, however, were testing only for the DNA of turkey, chicken, pork, beef and horse, so it is not known if the sausages may have contained other meats. Five per cent of the meat that was studied was unidentifiable.

Darren Devison of Toronto’s Royal Beef butcher shop has his own theory about the mystery meat: bad companies trying to save money.

“You could definitely have more exotic things,” he said. “I remember hearing stories about a company putting rat meat into sausages.”

Devison says that spices should be the only additive in sausages, and that the only reason why someone might use other meat is to save money.

“If you are charging a premium for something, it should be what you are saying it is,” he said.

While the test results don’t necessarily mean there were safety issues with the sausages, the findings may concern consumers who try to avoid certain kinds of meat, such as pork, for religious, medical or personal reasons.

Hanner, who is an associate professor with the Biodiversity Institute of Ontario at the University of Guelph, says the findings suggest there are gaps in our existing supply-chain traceability system.

But he added that the data are not altogether surprising given that studies from other countries have made similar findings. In fact, Hanner, said he thought “Canada is doing pretty well,” compared to others countries.

The Canadian Food Inspection Agency commissioned the study from Hanner after reports emerged in 2013 that undeclared horse meat was being found in ground meat products sold in grocery stores in the European Union.

That led to millions of products being pulled from shelves and several arrests across the EU for fraud.

Hanner says he doesn’t think the problem of meat mislabeling comes from the sausage producers.

“If the processors knew that certain meats were in the supply chain, they would probably put it on the label,” he said.

Instead, it is likely coming from further up the food supply chain.

“In a globalized economy, when we’re looking at very complex supply chains moving around the world, there’s just more opportunities for this kind of thing to happen,” he said.

Hanner noted the problem of “food fraud’ is not confined to the ground meat industry. It’s also been found to be rampant in the seafood industry, as well as the dairy and natural health products industries.

The CFIA investigated all 20 cases of mislabelled sausages, Aline Dimitri, the executive director of food safety science with the CFIA, told The Canadian Press.

She said, in the case of the chicken labelled as turkey, records for incoming meat and production records were not properly maintained. That problem was fixed, she said, and the CFIA is monitoring the company.

As for the horse meat in one sausage, the company involved has voluntarily ceased operations.

The CFIA is declining to identify the grocery stores where the mislabeled sausages were purchased.

“The results we saw did not lead to us determining that the product, in fact, is a hazard to human health,” Dimitri said.

The CFIA is planning a second sausage study where ingredients and grocery chains will be more rigorously scrutinized.

The initial study was not meant to outline the entire scope of the meat fraud issue in Canada. Instead it was designed to establish a baseline of the problem. It was also meant to test the DNA barcode testing tools used by Hanner.

DNA barcoding is a method developed at the University of Guelph that allows scientists to identify species of organisms using a short standardized region of their DNA.

Hanner said the testing method worked well.

“This study demonstrates that the technology is capable of monitoring the industry in a way we were never able to do before and is just one example of how DNA testing is becoming a standard for food ingredient authentication,” he said in a university announcement of the study findings.

With a report from CTV's Peter Akman in Toronto and files from The Canadian Press