Unnaturally high cane sugar levels were behind the New Zealand Food Safety Authority holding a $1 million honey order being exported from Timaru last month.

Honey Valley managing director Steve Lyttle told the Timaru Herald his production team had sent samples to Germany for testing and when the results came back "suggesting slightly unnatural levels", he contacted the authority.

The abnormality may be due to beekeepers feeding cane sugar to hives over winter, and not stopping early enough before harvesting.

It had been rumoured the order was seized over an issue with the honey's unique manuka factor (UMF), which indicates certain strains' antibacterial properties.

However, Mr Lyttle said the honey had not been seized and that a hold had been put on processing it while the authority investigated. As well, the honey showed "very good UMF activity".

He expected it would take several weeks before the authority could say whether the honey was suitable for sale.

"It could simply be a testing problem, but our company's policy is to play it safe and we are ultra-conservative with our testing approach."

- NZPA