With a glint in her eye and a seductive smile, a beauty from the past could hold the key to solving a mystery at the heart of one of the country’s most famous brands.

The unknown model was discovered on a chocolate box belonging to the founder of Bettys, Frederick Belmont.

The Swiss-born chocolatier, who had a spell working in Bradford and held royal patronage for creative chocolate flair, set up the company, which has become a household name.

But the question of why it is called Bettys and the inspiration behind the name has never been solved and is likely to have gone to the grave with Mr Belmont in the 1950s.

However, having uncovered the chocolate box from Mr Belmont’s archives, staff at the Harrogate-based company, which has a teashop in Ilkley, are wondering if this beautiful young woman could be Betty.

And they are hoping someone in West Yorkshire might be able to help them discover the model’s identity and possibly solve the company’s biggest riddle.

“It really is a mystery,” said Sarah Wells, who looks after the Bettys archives.

“People think we know who Betty was but we really don’t.

“Frederick Belmont died suddenly in the early 1950s and nobody got the chance to ask him who she was. Now we just have lots of theories.

“Maybe this model is her. She looks like she could be a film star if anything.”

Posing seductively in silk lingerie on a white polar bear rug and baring quite a lot of flesh, the model is on the chocolate box believed to date back to 1929. Now Miss Wells is hoping somebody might know something to help Bettys discover her true identity.

“We don’t know much about the box, to be honest,” she said.

“It is part of a selection of bits and pieces kept by Mr Belmont. He kept a scrapbook of adverts and lots of other things from the 1920s and 1930s.”

The mystery model is also the inspiration behind packing for a new range of Bettys chocolates which will be launched at the company’s tea rooms, including Ilkley, on November 11.

However, before she became the new face of Bettys chocolates, the company decided there was a question of decency to address.

And so on the new boxes of chocolates, the image of the unknown model has had a couple of extra buttons added to her clothes – to protect her modesty.

“We hear our founder had an eye for the ladies but even so, our mystery model was leaving very little to the imagination,” Miss Wells said.

“The sensuous slant of her garment suggests that a fine chocolate or two was simply a prelude to a passionate encounter.

“We would certainly not like to be thought prudish but as a family business we took the decision that an extra button or two on our new packaging would not come amiss.

“It’s dear to our hearts that Betty’s remains romantic rather than racy.”

If you know who the mystery model is or have some information about her, email sarah.wells@bettysandtaylors.co.uk