Commuters heading into Boston on the Massachusetts Turnpike over the weekend were surprised by a daring billboard unveiled near Fenway Park.

The advertising agency for Gosling's Rum is introducing an extremely rare rum by drawing a comparison to the missing member of Boston's well-known Bulger family.

“Almost as hard to find as Whitey Bulger,” says the billboard, which shows an expensive bottle of the “Gosling's Family Reserve Old Rum”.

Whitey was one of the leaders of the Boston “mob”, also referred to as the Irish Mafia and he has been on the run from the law for the better part of a decade.

According to Boston lore, an FBI agent tipped Whitey off that he was about to be apprehended, so he ducked out of town. He's been on the FBI's Most Wanted list ever since.

The president of the advertising agency that created the billboard, Glen Kelley, said Gosling's Rum might be one of the Island's biggest exports, but in the US it's a fairly new brand.

“We are competing against brands with marketing budgets much larger than Gosling's, so we had to create advertising that would stand out,” he said.

When they asked consumers to name other things that are very scarce, Whitey's name kept coming up, so they decided, just in Boston, they'd go with it.

The billboard will only be seen in this one location through the month of June.

Gosling's has three products in its line - the flagship brand Gosling's Bermuda Black Seal Rum, Gosling's Gold Bermuda Rum, and the Family Reserve Old Rum.

Malcolm Gosling, the seventh generation of his family to run the family business, moved to the US last year to support the American launch of his family's award-winning rums.