A New Zealand manuka honey producer who has offered to test what he calls a “rip-off” of manuka honey says fake versions of the health product cost the industry millions.

And he says educating consumers is the key to fighting the misleading claims on the labels of these shonky products.

Cornwall beekeepers have imported manuka plants from New Zealand to produce their own version of medicinal manuka honey which they are selling at £5 ($13) a teaspoonful.

Kerry Paul, chief executive of honey health science company Manuka Health New Zealand, said he was incredulous at the gullibility of British consumers and offered to test the Cornwall honey for levels of the active ingredient.

“If consumers are expecting that honey to have the antibacterial properties which genuine manuka honey is famous for, I’m afraid they will be disappointed,” he said.

But the problem is that consumers don’t understand the science behind the antibacterial properties of manuka honey and can be easily duped by misleading labels.

All types of honey have antibacterial properties, but only in genuine manuka honey is the antibacterial ability stable and reliable.

This is due to the chemical methylglyoxal, which is present in small amounts in other honey and some other forms of food but not in sufficient doses to actually have any antibacterial effect.

In other honey the antibacterial effect is caused by hydrogen peroxide; however it is not as stable or reliable as methylglyoxal and therefore useless for medicinal use.

And this has caused controversy over the different testing methods used to produce the number on manuka honey labels meant to signify antibacterial properties.

The established method tests the level of antibacterial activity and then subtracts the hydrogen peroxide component, but some companies “cheat” the tests by not doing this subtraction.

However, the MGO ™ test measures the amount of methylglyoxal in mg per kg.

The minimum is 100 and some products can have a level as high as 800.

Manuka honey is “like a fine wine” as the methylglyoxal level increases over time as glucose in the honey breaks down.

Mr Paul said manuka honey health product exports were worth about $60 million to the New Zealand economy, and scams like the British one are damaging.

“The costs of producing manuka honey are far higher than for normal table honey. They take what is mostly table honey and sell it at two thirds of the manuka honey price.”