The deep-fried Mars bar has joined Scotland’s culinary pantheon / Alamy

Manufacturer disowns Scottish delicacy and demands a disclaimer

When Forrest Mars formulated his nougat-and-caramel chocolate bar at a factory in depression-hit Slough, he could scarcely have anticipated that 60 years later an enterprising Scottish fish-shop owner would dip his famous confection in batter before plunging it into sizzling fat.

The Stonehaven deep-fried Mars bar became an international phenomenon in the 1990s and rapidly joined Scotland's culinary pantheon alongside haggis, the Arbroath smokie and Irn-Bru – even if it did horrify public-health officials grappling with a population suffering some of the worst obesity rates in the developed world.

But now, 20 years since chocolate first met chip fryer, the global food brand has written to the humble Scottish chippie that transformed its flagship product, asking it to publish a disclaimer at the bottom of its menu distancing the company from the snack. The Carron Fish Bar, which counts the £1.30 fried treat as one of its biggest attractions, selling up to 150 a week, has been told that the "recipe" contradicts Mars's commitment to healthy eating – a move that was signalled in 2010 when it cut the saturated fat content of the eponymous bar by 15 per cent, reducing it to 260 calories a time.

"Deep frying our Mars bar product, of course, counters this significantly," the letter said. "To avoid any consumer confusion in this respect, we would be grateful if you would insert a small disclaimer at the bottom of any menus you may have and a sign on display at your shop stating as follows: 'Mars is a registered trade mark of Mars Incorporated. Our use of Mars is not authorised or endorsed by Mars Incorporated.'"

The Carron Fish Bar's owner, Lorraine Watson, said she was shocked at the move, which followed her inquiries about registering the deep-fried Mars bar under the EU's Protected Food Name Scheme – an accolade afforded to specialities such as Parma ham and Champagne.

"I was amazed when I got the lawyer's letter because I really feel they are giving me a slap on the wrist when I haven't tried to offend them," Ms Watson said. "We have been selling this deep-fried Mars product for 20 years and this is the first time we have heard from Mars. Have I really offended them that much? I think it's sad that it's come to this."

Ms Watson has since abandoned the idea of securing protected status, deciding it would involve too much paperwork. The manager, Doug Craig, who has been frying Mars bars for the past five years, said the recipe remained unchanged since it was first invented by local schoolchildren in 1992. The bar is chilled to prevent melting and dipped in flour before being coated in batter and fried until golden brown. A study published in The Lancet in 2004 surveyed 300 Scottish chippies and found that 22 per cent sold deep-fried Mars bars while a further 17 per cent had done so recently.