A Chicago radio show says it has revealed Coca-Cola's secret recipe, a mystery since the soda was created in 1886. (Seth Perlman/Associated Press)

A Chicago Public Radio program says it has uncovered "one of the most  jealously guarded trade secrets in the world," the original recipe for Coca-Cola — a claim the company is disputing.

The ingredients that make up one of the most popular soft drinks in the world had supposedly been a mystery since John Pemberton created the drink in 1886.

According to the radio program This American Life, however, a photo of the coveted recipe was published in the Atlanta Constitution-Journal in 1979.

The recipe consists of two parts: caffeine, sugar, caramel and vanilla, but also "fluid extract of coca."

The second part — an exotic concoction called "Merchandise 7X," which includes cinnamon, nutmeg oil, neroli, orange oil and coriander — gives the pop its distinctive flavour, the radio show said.

Coca Cola Co., however, denies that the recipe found by the radio program is the same as the one it keeps in an Atlanta, Ga., bank vault. 

Many third parties have tried to get the formula, Coke said. "Try as they might, they've been unsuccessful, because there is only one 'Real Thing,'" Reuters news agency quoted spokeswoman Kerry Tressler as saying.

It also reported that the company archivist said the found recipe matches another one in a notebook owned by Pemberton that is in Coke's archives. The archivist said it might be a precursor to the one that went to market, but not the real thing.