Australia's biggest listed honey company and some of the country's largest supermarket chains face accusations of unwittingly selling "fake" honey.

Testing at a leading international scientific lab that specialises in honey fraud detection has found that almost half the honey samples selected from supermarket shelves were "adulterated", meaning it has been mixed with something other than nectar from bees.

The adulterated samples were all products that blend local and imported honey.

ASX-listed Capilano's Allowrie-branded Mixed Blossom Honey, which sources honey from Australia and overseas, and markets itself as 100 per cent honey, showed up as "adulterated" in the majority of samples tested.

Capilano strongly denied any issues with its products and criticised the type of test — known as Nuclear Magnetic Resonance (NMR) — used to detect the impurities, pointing out that it differed from the official Australian test.

There is no suggestion that Capilano's eponymous brand of Australian-sourced honey has any issue or that Capilano or other brands were aware of the adulteration.

Phil McCabe, the president of the International Federation of Beekeepers' Association (Apimondia), believes the NMR test is the most accurate available and thinks consumers are not getting what they paid for.

"Adulterated honey isn't honey at all," he told 7.30.

"By and large [the impurity] is some kind of syrup that's been converted to look like honey, it tastes like honey.

"Everything about it seems to be honey, when in fact it's just sugar syrup or something else.

"Consumers don't realise what they are buying and eating isn't honey."

Almost 50 per cent of samples tested 'adulterated'

Robert Costa bankrolled the tests of the honey samples. ( Supplied: Fairfax )

The results are set to ignite a storm over how honey purity is tested that will involve the Federal Government as well as local and international regulators.

Supermarket chain, ALDI, has already moved to pull any affected product from its shelves as a precaution.

Mr McCabe said he would refer the tests, obtained by Fairfax Media and 7.30, and commissioned by top law firm King & Wood Mallesons, to Interpol for further investigation.

Germany's Quality Services International (QSI) lab was commissioned by the law firm on behalf of horticulturalist Robert Costa to conduct two types of tests of the sampled honey.

One used NMR screening and the second used the official C4 sugar test.

The joint media investigation into the honey industry was supplied a copy of the results from Mallesons.

The law firm collected 28 blended and imported honey samples from supermarket stores around Australia, including Coles, Woolworths, ALDI and IGA and documented the stores, locations, brands and batches.

Beehives in an orchard near Mildura. ( ABC News )

The lab tested eight Allowrie samples as well as IGA's Black & Gold private label and ALDI's Bramwell's private label brand, which are blended local and imported honey, and detected adulteration in almost half the samples.

Using the NMR testing the results showed that 12 of the 28 samples tested were not 100 per cent pure honey.

Four of the six IGA Black and Gold private label products registered as adulterated, two of six ALDI Bramwell's private label brands failed the NMR test and six out of eight of Capilano's Allowrie budget branded bottles had adulterated honey when NMR screening was used.

The same 28 samples were then tested using the official Australian test, C4, and all passed.

We stand by the quality and purity of our honey: Capilano

Capilano says that its Allowrie brand of honey is pure. ( ABC Rural: David Claughton )

Capilano was sent a copy of the results of the tests.

It vigorously denied that any of its products were not pure honey and rejected NMR testing as the best way to determine adulteration.

It said Australian and international regulators "do not use this testing regime at all."

Capilano said it was 100 per cent confident its Allowrie honey, which is made using up to 70 per cent imported honey, was pure and that it was not surprised by the results given the "weaknesses" in NMR testing as an analytical method.

"We are incredibly concerned that they are being used in isolation of more robust analytical testing, given this is also the opinion of the manufacturer [Bruker] and the two most reputable laboratories in the world [Intertek and QSI], one of which has conducted the NMR analysis," Capilano said in a statement.

"Our concern lies in the use of these results to create doubt and confusion over the authenticity of honey and how that could be used to mislead the public and consumers."

Capilano said one of those weaknesses was that the NMR test did not detect that blended honey from different regions was 100 per cent honey, something the German lab, QSI, vigorously denies.

Capilano declined an interview but said it "stands by the quality and purity of all of our honey brands, including Allowrie which has never failed more stringent and appropriate testing by world renowned laboratories."

Capilano says that two samples from the same batch came back with different results from the two labs using NMR.

Honey testing at QSI labs in Germany ( ABC News )

QSI's managing director Gudrun Beckh, who has been testing honey for almost 30 years, said she was confident in the NMR test findings and said if a sample showed up as adulterated it meant the honey was not pure honey.

"Fake honey always existed, but in the last years it's a growing problem because of the people who adulterate using more and more sophisticated methods, so it's more complicated to detect it," she told 7.30.

QSI performs a variety of tests for clients but Ms Beckh said NMR was the best for detecting adulteration.

She said QSI had an extensive database and used various tests for testing honey but NMR was the most reliable.

She said blended honey from different regions was tested regularly and NMR screening could pinpoint country of origin and botanical origin of the honey.

In the tested samples, she said it was the Chinese aspect of the honey that was adulterated not the Australian honey.

Despite Capilano's criticisms there is a groundswell of international experts, academics and private companies increasingly relying on NMR as the test of choice for detecting fake honey.

Apimondia, the peak body for the sector internationally, recently said it would use NMR screening as part of its new honey competition rules.

Leaked emails from the local peak industry group, the Australian Bee Industry Council (AHBIC), of which Capilano is a financial member and has board representation, show it wrote to the Department of Agriculture and Water Resources in July requesting it review the way it tests honey, ditching the old C4 test and moving to NMR.

The executive director of AHBIC Trevor Weatherhead said in the email to the department that "AHBIC would ask the department to change to the NMR test if it has not done so already."

He said it was reported that suppliers that were adulterating honey were finding ways around the C4 sugar test.

"The NMR test has been found to be very effective," Mr Weatherhead said in an email.

'It's time to speak up, before it's too late'

Jodie Goldsworthy, of Beechworth Honey, says it's time to speak up about adulterated honey. ( Supplied: Fairfax )

Fairfax and 7.30 also contacted IGA, ALDI, Coles and Woolworths about the results of the tests.

At 2pm on Friday ALDI temporarily withdrew the two products in its Mixed Blossom Honey range that QSI identified as "adulterated".

ALDI said it would investigate the claims and if the investigations conclude that the product has been adulterated, it would permanently be removed from sale at ALDI and further actions would be taken with the supplier.

Woolworths said it treated the accuracy of product labelling very seriously.

"We will now work closely with our supplier to review the substance of the claims in detail before determining our next steps," it said.

Coles said it had deleted all Allowrie products from its shelves for unrelated reasons in July after a range review.

IGA said it meets all the requirements of the Australian and New Zealand food code.

Mallesons was expected to send a copy of the test results to the Australian Competition and Consumer Commission (ACCC) on Monday.

Mr Costa, who bankrolled the honey sample tests, said his concern as a horticulturist was that cheap imported honey was hurting the local industry, which, in turn, would hurt the production of agriculture.

He estimated that 65 per cent of agriculture depended on pollination by honey bees.

"We know what's going on, we expected it, we just needed the evidence," he told 7.30.

"I certainly wasn't shocked."

Beechworth Honey, Australia's second-largest honey operator and a major competitor to Capilano, said it only used Australian honey.

Beechworth managing director Jodie Goldsworthy said she supported NMR testing as the best way to detect adulteration.

Ms Goldsworthy said beekeepers of the world had largely been silent about the problem of adulterated honey for fear of hurting the reputation of the industry.

"The silence has made it really easy for the frauds to go on unhindered," she said.

"It's time to speak up before it's too late."

See more tonight on 7.30.