British consumer rights group Which? yesterday published the results of tests conducted on 76 samples of goats' cheese bought in supermarkets, delis, and markets in eight locations across the UK.
Of the 76 samples tested, nine were found to contain sheep's milk protein.
Of these, three items were found to contain more than 80% sheep's cheese.
Another three contained more than 50%, and the remaining three contaminated samples consisted of around 5% sheep's cheese.
On the back of the Which? study, the FSA has promised a full investigation.
“Consumers have a right to expect that food is what it says on the label,” said statement issued by the FSA.
“We take any suggestion of food fraud seriously, and we will investigate with the relevant local authority any business supplying mislabeled products when we receive the details from Which?”
Suspicious about the large amount of goats' cheese on sale in the UK despite a current goats' milk shortage, Which? drafted in Queens University Belfast's Professor Chris Elliott, author of a recent independent review of UK food systems, to investigate.
"We tested the goats' cheese samples for a wide range of different animal species," Elliott said in a post published on the Which? website. "I had actually expected to detect some adulteration with cow's protein but what we found was substantial amounts (more than 50% in this example) of sheep protein in six cases out of 76."
Elliott added that in four of the six significant cases of contamination, the sheep's milk protein originating outside the UK was detected.
"My message is not that all things foreign are bad, but that when supply chains are long and lack local knowledge and long term relationships there must be more opportunities for cheating and thus more checks are needed."
Supporting this theory, Nigel White, secretary, British Cheese Board, said he would be "really surprised if the cheese that tested positive were made in the UK."
According to White, goats' milk currently sells for around 50p per litre, whereas a litre sheep's milk is currently priced at around £1.00.
"It seems strange because there is no economic incentive to use sheep's milk," told DairyReporter.com.
"It could be that there is surplus sheep's milk available in somewhere like France that has been sold off cheaply."
"I'm at a bit of a loss to explain it," he added.
The Trading Standards Institute (TSI), which represents tradings standards officials across the UK, meanwhile took the opportunity to criticize government cuts.
Leon Livermore, CEO, Trading Standards Institute, told DairyReporter.com it was "only luck" that these cases of adulteration had come to light.
“Trading Standards officers strive to stamp out food fraud in their authorities and will work to address this issue where they can. Consumers deserve to know what they are eating, and businesses buying products deserve to have confidence in their suppliers,” said Livermore.
“However, I feat that with savage cuts to trading standards services hampering efforts to test and investigate, it is only luck that these types of frauds aren’t putting consumer’s safety at risk. We might not be so lucky with the next scare.”