Authorities working with the FBI in eastern Europe have foiled four attempts in the past five years by gangs with suspected Russian connections to sell radioactive material to Middle Eastern extremists.
The latest known case came in February, when a smuggler offered a huge cache of deadly caesium - enough to contaminate several city streets - and specifically sought a buyer from the Islamic State (IS) group.
Criminal organisations, some with ties to the Russian KGB's successor agency, are driving a thriving black market in nuclear materials in the tiny and impoverished country of Moldova, investigators say.
The successful busts, however, were undercut by striking shortcomings. Kingpins got away and those arrested evaded long prison sentences, sometimes quickly returning to nuclear smuggling.
Moldovan police and judicial authorities have shared investigative case files with the media in an effort to spotlight how dangerous the nuclear black market has become.
They say the breakdown in co-operation between Russia and the West means that it has become much harder to know whether smugglers are finding ways to move parts of Russia's vast store of radioactive materials - an unknown quantity of which has leached into the black market.
"We can expect more of these cases," said Constantin Malic, a Moldovan police officer who investigated all four cases. "As long as the smugglers think they can make big money without getting caught, they will keep doing it."
In wiretaps, videotaped arrests, photographs of bomb-grade material, documents and interviews, a troubling vulnerability was found in the anti-smuggling strategy.
From the first known Moldovan case in 2010 to the most recent one in February, a pattern has emerged: authorities pounce on suspects in the early stages of a deal, giving the ringleaders a chance to escape with their nuclear contraband - an indication that the threat from the nuclear black market in the Balkans is far from under control.
Moldovan investigators cannot be sure that the suspects who fled did not hold on to the bulk of the nuclear materials. Nor do they know whether the groups, which are pursuing buyers who are enemies of the West, may have succeeded in selling deadly nuclear material to extremists at a time when IS has made clear its ambition to use weapons of mass destruction.
The cases involve secret meetings in a top nightclub, blueprints for dirty bombs and a nerve-shattered undercover investigator who slammed vodka shots before heading into meetings with smugglers.
Why are you making commenting on The Herald only available to subscribers?
It should have been a safe space for informed debate, somewhere for readers to discuss issues around the biggest stories of the day, but all too often the below the line comments on most websites have become bogged down by off-topic discussions and abuse.
heraldscotland.com is tackling this problem by allowing only subscribers to comment.
We are doing this to improve the experience for our loyal readers and we believe it will reduce the ability of trolls and troublemakers, who occasionally find their way onto our site, to abuse our journalists and readers. We also hope it will help the comments section fulfil its promise as a part of Scotland's conversation with itself.
We are lucky at The Herald. We are read by an informed, educated readership who can add their knowledge and insights to our stories.
That is invaluable.
We are making the subscriber-only change to support our valued readers, who tell us they don't want the site cluttered up with irrelevant comments, untruths and abuse.
In the past, the journalist’s job was to collect and distribute information to the audience. Technology means that readers can shape a discussion. We look forward to hearing from you on heraldscotland.com
Comments & Moderation
Readers’ comments: You are personally liable for the content of any comments you upload to this website, so please act responsibly. We do not pre-moderate or monitor readers’ comments appearing on our websites, but we do post-moderate in response to complaints we receive or otherwise when a potential problem comes to our attention. You can make a complaint by using the ‘report this post’ link . We may then apply our discretion under the user terms to amend or delete comments.
Post moderation is undertaken full-time 9am-6pm on weekdays, and on a part-time basis outwith those hours.
Read the rules hereComments are closed on this article