This has been a long-standing problem, and is a sort of arms race between the fakers and the analysts,
It was first noted after the oil supply problems about 30 years ago, when the yanks decided to get alcohol fuel as an alternative. They invested heavily in bioethanol from Maize, the trouble was that you got high fructose corn syrup as a by-product. That looks and tastes very similar to honey from oil-seed rape but it was found that the sugars are slightly different, but only in the carbon-11 to C12 ratio. When that loophole was closed the (mainly Chinese) fakers started offering sugar syrups which couldn't be distinguished that way and had the nerve to blatantly offer it in all sorts of "honey" flavours, but the adverts for bulk chineses stuff seem to be suppressed nowadays.
There have been a succession of tests but the UK won't pay to do them so we are where we are now. That government statement
is evasive and hides the fact that trading standards is woefully underfunded and nothing is being done. The BBKA has been going on about it for years, a recent petition for accurate labelling (to accurately declare countries of origin) got nowhere as I think it would impact the Party donors who make money by selling honey below the cost at which it can be produced.“If this study does not trigger a broad and serious investigation in the UK like the one in the EU, then either the UK are completely incompetent or they are complicit.”
The government disputes claims that honey imports are adulterated on an industrial scale. It has previously said there is “insufficient evidence” to date to indicate fraud and the enforcement is “fit for purpose”.
A spokesperson for the Department for Environment, Food and Rural Affairs said: “The UK government takes any type of food fraud very seriously – including honey adulteration. There is no place for adulterated honey which undermines consumer confidence and disadvantages responsible businesses.
“We work closely with enforcement authorities to ensure honey sold in the UK is not subject to adulteration, meets our high standards – and maintains a level playing field between honey producers.”