With manuka honey prices hitting record highs (as much as £45 per jar), we reported that health food stores and supermarkets were introducing measures to clamp down on discerning thieves (17 August) to flog on eBay. But oh the bitter sweet irony. It turns out the bigger felony against retailers (and consumers) was actually being committed by unscrupulous suppliers. In late August, the FSA issued a nationwide trading standards alert amid evidence that much of it is fake.

Tests carried out by the Food and Environment Research Agency (Fera), the scientific arm of Defra, along with overseas studies, found much of the honey labelled as manuka was nothing more than ordinary baker’s honey. And research by the main honey producers’ organisation in New Zealand - where almost all the world’s manuka honey derives - revealed that 1,700 tons of manuka were produced there each year, compared with the estimated 1,800 tons of “manuka” honey sold in the UK alone. As much as 10,000 tons are sold worldwide.

John Rawcliffe of the Unique Manuka Factor Honey Association (UMFHA), which represents New Zealand’s producers, said: “There is potentially huge fraud. There are higher and ever-increasing volumes of honey labelled as manuka that are not manuka. More manuka is sold in the UK alone than the total actually produced. The same applies to China, America and so on.”

Manuka honey is produced by bees whose hives are placed near flowering wild manuka bushes that grow mostly on New Zealand’s North Island. Until 1981, when a New Zealand scientist found it had powerful anti-microbial properties, it was classed as a low-grade honey and used in cattle feed.

In October 2011 Fera tested five brands of manuka honey sold in the UK. Only one showed the “non-peroxide” anti-microbial activity that is unique to genuine manuka honey. In further tests of 23 manuka-labelled honeys, 11 failed the non-peroxide test.

The UMFHA commissioned more tests in 2012 and also this year in Britain, China and Singapore. Of 73 samples tested, 41 showed no non-peroxide activity. Separate tests in Hong Kong found that of 55 manuka honeys sampled, 14 had been adulterated with syrup.

The FSA said all trading standards authorities had been “asked to make sure anyone selling manuka honey is aware that they must fully comply with the law”.

Sterilised manuka has been shown to help skin to heal when used in wound dressings. However, there is no clinical evidence that eating manuka honey aids health.

Despite this it has enjoyed soaring popularity - and sales - thanks to clever marketing and its endorsement by celebrities. For example, the Welsh singer Katherine Jenkins says it helps to prepare her throat for performances and the world’s No1 ranked tennis player, Novak Djokovic praises manuka honey in Serve to Win, his book about his diet. Hollywood actress Scarlett Johansson says she uses manuka beauty products on her skin.

Patrick Robinson, chairman of the British Honey Importers and Packers Association and operations director at Rowse Honey, the UK’s largest honey producer, agreed that manuka authenticity was a concern. “Every batch of our honey is tested and labelled properly,” he said.

Read The Grocer’s Review of the Year 2013.