It is not widely reported, but European firearms for a long time have played a pernicious role in US mass shootings and Europe's gun makers are among the strongest backers of the National Rifle Association (NRA).

Handguns by Austrian arms manufacturer Glock and German-owned SigSauer were used in the most recent massacre in December 2012 in Newtown, Connecticut that left 20 children and eight adults dead.

A Glock gun was also used in the shooting spree inside a movie theater in Aurora, Colorado in July 2012 in which 11 people were killed.

A semiautomatic weapon by the Austrian gun producer again featured in the January 2011 massacre in Tucson, Arizona in which six people were killed and congresswoman Gabrielle Giffords was seriously injured.

Two guns by Italian manufacturer Beretta were used to kill 14 people in Binghamton, New York in April 2009.

And the worst massacre by a single gunman in US history was also perpetrated with European weapons: The Virginia Tech killing spree that left 33 people dead in 2007 was carried out with a German Walther and an Austrian Glock gun.

All guns used were purchased legally.

This list is by no means exhaustive, rather it is just the tip of the iceberg. European guns feature not only prominently in mass shootings, but they are a major player in US civilian gun sales.

Europe corners a quarter of US gun sales

"If we are looking at 2010 that is the latest year for which we have good data overall for the civilian market, excluding military purchases, we are looking at about 26 percent of the guns entering the market being of European origin," Nicholas Marsh, a small arms expert at the Peace Research Institute Oslo, told DW.

Austrian Glocks are among the most popular guns in the US

With a quarter of the civilian gun market in European hands, the continent is by far the biggest international seller into the US, dwarfing sales from Asia and Latin America. According to the latest governmental figures from the Bureau of Alcohol, Tobacco and Firearms (ATF) some two million of the roughly eight million firearms within the US domestic gun market in 2010 were European-made or owned.

More than a dozen European nations - from Poland to Portugal, from Bulgaria to Britain - export guns to the United States to be sold to American citizens. But the lion's share of European exports to the US stems from only three countries: Austria, Italy and Germany.

Exporting 434,374 firearms - almost exclusively handguns - to the US in 2010 according to the ATF, Austria clearly leads the pack.

Italy comes in second with 285,083 firearms destined for US civilians. Germany ranks third with 266,688 guns exported for the American market, according to the ATF.

While most European guns sold in the US are imported, large players like Austria's Glock, Italy's Beretta or Germany's SigSauer also produce guns directly at subsidiaries in the US.

Dependency on US sales

Since most European gun makers are private companies precise sales and profit figures for their US exports are hard to come by. The trade group National Shooting Sports Foundation estimates that the size of the US civilian firearms market, the largest in the world, amounts to around $4 billion (3 billion euros) per year. With guns of European origin cornering about a quarter of that market, sales to American costumers are certainly a lucrative business.

"They are extremely important," explains Marsh. "The most extreme example is Croatia." The country ranks fourth among European gun exporters to the US and according to ATF figures in 2010 shipped 239,021 arms - only handguns and practically all from Croatian arms producer HS Produkt - across the pond.

US civilians are a major target group for European gun makers

"We did a study a few years ago and 98 percent of exports from Croatia went into the United States," adds Marsh. "So basically a country can become a sort of mid-level exporter by global standards just by acquiring a sort of niche in the US civilian market."

Walloon government-owns prominent gun maker

What's more, selling guns to American citizens is apparently such a good business, that even European governments want a slice of the pie. The Belgian Herstal group which owns arms maker FN Herstal as well as the well-known American brand Browning, is "100 percent owned by the Walloon Region of Belgium," as the firm proudly proclaims on its homepage.

"For more than 15 years now that group is in the hands of the Walloon government of Belgium, which means this is actually a government enterprise," Nils Duquet, a small arms researcher at the Flemish Peace Institute in Brussels, told DW. While Belgium and the Herstal Group are not one of the largest European civilian arms exporters to the US, the group's production site is nevertheless a major employer in the economically depressed Walloon region of Belgium, adds Duquet.

Most European gun makers are not as dependent on US sales as Croatian manufacturer HS, but tougher gun laws in the US as proposed by President Barack Obama would definitely hurt what until now was a booming business.

"Certainly they would have severe financial problems if the US civilians would completely stop buying firearms one year," says Marsh. That won't happen anytime soon, but even the relatively modest restrictions on the table now could cut into their sales.

Europe's arm producer give millions to NRA

To counter any possible tightening of American gun laws, European companies do the same thing their US counterparts are doing: Support the NRA's fight against tougher gun laws.

European arms producers support the NRA with millions of dollars

The list of its biggest donors, honored by the NRA at the organization's annual meeting in April 2012, reads like a "Who's Who" of European arms manufacturers.

According to data published by the Washington-based gun control group Violence Policy Center (VPC), Italian-owned Beretta USA donated between $1 million to 4.9 million and its sister company Benelli USA gave between $500,000 to $999,000.

Austrian-owned Glock USA and German-owned Blaser USA donated at least $250,000 up to $499,000.

Walloon-government owned brands FNH USA and Browning helped the NRA out with at least $50,000 to $99,000, respectively, as did German-owned Krieghoff International.

German-owned SIGARMS gave between $25,000 to $49,000.

Even if one just takes the minimum sums listed, these European gun makers gave the NRA at least $2.175 million in 2012. That figure does not include any smaller donation not publicized by the NRA.

Neither the European gun makers donating to the NRA nor Belgium’s Walloon government responded to DW’s questions about their conduct.

The refusal by European arms producers to answer questions about their involvement with the NRA is part of their strategy, note the experts:

"They try to remain silent in the public eye, but they definitely have connections with all the lobby groups that try to influence legislation in the US," says Duquet. "Basically what they want to do is sell their products. And the looser the law, the more they can sell their product. So for them it’s pretty simple."

Double standard

While small arms experts Duquet and Marsh are not surprised by the close connection between the NRA and other gun lobbyists in the US and European companies, they criticize what Duquet calls a European "double standard."

"It's quite striking how Europeans often like to view their society as being more peaceful and less violent than the US," says Marsh. "You have lots of Europeans who in the last month or so have suggested that the US needs to adopt a sort of European-style firearm regulation regime."

At the same time, adds Marsh, European firms are making a lot of money supplying the US market. "Those companies' profits are being taxed by the governments. The governments are licensing these exports" and "people are sitting in Europe happily making the money and issuing the export licenses."

Europe should question its role in the US gun market, say experts

It's high time for a public debate about European gun exports, argue the experts.

"We need first more awareness being raised about the links between the European industry and the civilian market in the US," says Marsh. "This is very rarely remarked upon. And second there needs to be a question as to whether it's a good idea to have pretty much unrestricted sales into the US market."