At the Isabella Stewart Gardner Museum in Boston, the Dutch Room is home not only to timeless works of art by Rubens, Dürer, and Van Dyke but to several gilded frames whose emptiness bear witness to the biggest art heist of all time. As St Patrick’s Day was drawing to a close in 1990, around half a billion dollars worth of precious art was stolen by two men dressed as police officers. The paintings have never been seen in public since.

The unsolved mystery has experienced a resurgence in the media in recent weeks following the grisly death of criminal mastermind James “Whitey” Bulger — the former mob boss was beaten to death by fellow inmates while serving two life sentences in prison.

As per Charles Hill, former Scotland Yard detective and private investigator, Bulger was a leading figure in the 1990 heist, having arranged for the paintings to be shipped to Ireland as part of a deal with the Irish Republican Army (IRA). The renewed speculation that the IRA was responsible for — or at least benefited from — the infamous heist has shone a spotlight on the murky connections between Crime and art.

Asking ransom for paintings a common IRA tactic

The sensational story, if proved true, is hardly the first time the IRA has been linked to stolen art. In the 1970s and 1980s, two raids on the Ireland country home of Sir Alfred Beit targeted a similar collection of priceless works, which were eventually recovered.

In 1974, an IRA gang raided Russborough House of 19 paintings to the tune of £8 million - including a Vermeer, a Goya, three Rubens and two Gainsboroughs. Sir Beit himself, 71 years-old at the time, was struck with a revolver before being tied up in the library with one of his staff, where he was forced to watch the gang cut his precious paintings from their frames with a screwdriver.

The IRA then attempted to hold five of the most valuable paintings stolen in the incident as ransom, in a bid to have four members held in an English prison for bombing London transferred to Belfast. The group’s plan was thwarted just eleven days later, when a raid on a rented cottage in Glandore, County Cork, recovered all the paintings seized in the heist.

One notable gang member arrested in the wake of the 1974 incident was British heiress, Dr Rose Dugdale. Dugdale was an unlikely candidate for an IRA terrorist — raised on a 600-acre estate in western England, presented to Queen Elizabeth as a debutante, she was educated at Oxford and the elite Miss Ironside's School for Girls. After having been radicalised during the international student riots of 1968, Dugdale cashed in shares she had inherited and donated her wealth to London’s poor, embarking on a campaign as “freedom fighter” that would ultimately see her give birth to a son in Limerick Prison months after the Russborough robbery.

Similar tactics in other criminal organisations

Nor is the IRA the only criminal organisation to dabble in art theft.

In Sicily, the Cosa Nostra has built a tidy profit on the acquisition and sale of ancient antiques, a business they have recently expanded in tandem with the Neapolitan Camorra to include art stolen by terrorists in Libya.

In September 2016, anti-Mafia police chanced upon two Van Gogh masterpieces worth $100 million wrapped in just a bed sheet, tucked under the stairway of a gangster’s home near Naples. According to Dutch art detective Arthur Brand, the Neapolitan Camorra likely has a cache somewhere of stolen paintings seized from the Vincent Van Gogh Museum in Amsterdam in 2002.

More than decoration — a flexible asset

As banking rules have tightened, valuable art has filled the gap as a convenient asset for organised criminals.

Over the past half-century, international crime groups have not just been responsible for the majority of art thefts and sale of forgeries, but have used profit from their dabblings in the art world to fund their operations in drug trafficking, arms trading, and terrorism.

At the same time, barely five per cent of stolen art is ever recovered, with gangs often left holding on to valuable works, unable to sell them — forced instead to wrap them in bed sheets and tuck them under staircases, for example. Those who do try to liquidate their holdings, as one gang in Italy did with a 15th-century manuscript, risk being caught and the precious artwork seized.

Art theft an often overlooked crime

Despite this widespread connection between art and antiquities theft and international criminal networks, there has been a tendency on the part of both the public and law enforcement not to take art crimes seriously, dismissing them as merely the looting of the extravagant possessions of the upper echelons of society.

By way of example; Scotland Yard’s Art and Antiques Unit has been under threat of closure for years, despite the very real threat posed to public security by the rise of precious artworks as criminal currency.

The notion of stolen masterpieces on behalf of cinematic villains resembling James Bond’s Dr No belongs only to the realm of Hollywood. “It’s almost never stolen because it’s a beautiful object,” remarked Vernon Rapley, who headed the Scotland Yard unit for a decade before joining the V&A Museum as head of security, “rather, it’s a commodity that can be used as collateral for other illicit activity.”

From Mexico to the Middle East, the seizure of historic artefacts, cultural gems and priceless works of art is quickly becoming the lifeblood of the darker sides of global criminal gang activity. With mounting evidence that art theft cannot be untied from international terrorist organisations, it’s time to face facts: art heists are far from the public curiosity they are currently framed as.