A Food Standards Scotland board member who has financial links to a chocolate manufacturer has been criticised after she argued against a sugar tax on food.

Carrie Ruxton, who has advised confectionery giant Ferrero - of Ferrero Rocher fame - is said to have expressed “serious reservations” about FSS advocating the tax.

Launched in 2015, the FSS was set up to provide information and advice on food safety and standards, nutrition and labelling.

However, the body recently became embroiled in a conflict of interest row over the outside financial interests of Dr Ruxton, a dietician.

As well as being paid to advise Ferrero, she once chaired a panel event for the British Soft Drinks Association and worked in the 1990s for The Sugar Bureau, which used to be the voice of the industry.

Before joining the FSS in 2015, she also received funding from Coca Cola to give a talk on artificial sweeteners.

Internal FSS emails released to the Sunday Herald reveal Ruxton questioned whether the body’s high-profile support for a sugar tax applied to food.

According to FSS, the board backed a “tax on sugar content" for food and drink in January 2016.

By March this year, the details of the tax came back to the Board and Ruxton was on the side of restricting it to fizzy drinks.

In an email to FSS board chair Ross Finnie, she wrote: “At the board meeting, you expressed an interest in seeing the evidence that sugar overall was not found to relate to obesity or weight gain, while sugar from beverages was found to relate to body mass index and weight gain”.

She attached a document on this subject as well as an external analysis.

She continued: “This leads me to understand that a narrow fiscal focus on the sugar content of foods may result in the unintended consequence of reformulation which lowers sugar, but not calories, therefore having no impact on population risk of obesity.”

In response, Finnie noted that Ruxton had expressed “serious reservations” at the board on “our advocacy of a sugar tax”.

He wrote: “I was surprised at your stance because when we adopted our position of not ruling out a sugar tax in January 2016 you expressed no such reservations.”

Finnie added: “I take any reversal of support for an agreed policy by a Board Member very seriously and have, therefore, discussed both your position and your supporting papers extensively within the office.”

He added: “I am of the view that, contrary to your assertion at the Board, both the scientific evidence and the argumentation that flowed from that evidence continues to support the Board.”

Ruxton replied by saying her understanding of the FSS tax proposal was that it focused on beverages, adding that it was “not made clear” it would be extended to food products.

She wrote: “My fear is that a wider sugar levy may indeed drive down the sugar content of foods but not the calories.."

However, she described any suggestion of her going back on a collective decision as “misplaced”.

In his final email, Finnie said: “The Board agreed to the principle of a broad sugar tax and sought to explore how that might be constructed and introduced which does not appear to be your position.”

Dr Ruxton has always declared her financial links to food companies on her register of interest, and there is no suggestion of impropriety on her part.

Joanna Blythman, an award-winning investigative food journalist and author as well as a columnist for the Sunday Herald, said: "Dr Ruxton’s position on the FSS board is now untenable.

“It is simply unacceptable that someone who actively attempts to downplay the very real damage that sugar does to public health should be on the FSS board, the public body charged with dispensing nutrition advice to the public. This is a blatant conflict of interest.”

Asked if the chair still had faith in Ruxton as a board member, an FSS spokesperson said: “There has been no impropriety on the part of Carrie Ruxton and, accordingly the Chair continues to have faith in Carrie as a Board member. Carrie’s reservations on the effect of introducing a sugar tax have been clarified and will feed into Food Standards Scotland’s work on how a sugar tax might be introduced, not whether a sugar tax is to be introduced.

“Food Standards Scotland does not believe that any individual who works or has worked in the food sector should automatically be barred from being a member of the Board. Equally, Food Standards Scotland is clear that all members of the Board must declare all of their interests in the Register of Interests and must declare such interests when an item of Board business gives rise to a potential conflict of interest.”