BATUMI, Georgia (AP) -- On the gritty side of this casino resort town near the Turkish border, three men in a hotel suite gathered in secret to talk about a deal for radioactive material.
The Georgian seller offered cesium, a byproduct of nuclear reactors that terrorists can use to arm a dirty bomb with the power to kill. But one of the Turkish men, wearing a suit and casually smoking a cigarette, made clear he was after something even more dangerous: uranium, the material for a nuclear bomb.
The would-be buyers agreed to take a photo of the four cylinders and see if their boss in Turkey was interested. They did not know police were watching through a hidden camera. As they got up to leave, the police rushed in and arrested the men, according to Georgian officials, who were present.
The encounter, which took place in April, reflected a fear shared by U.S. and Georgian officials: Despite years of effort and hundreds of millions of dollars spent in the fight against the illicit sale of nuclear contraband, the black market remains active in the countries around the former Soviet Union. The radioactive materials, mostly left over from the Cold War, include nuclear bomb-grade uranium and plutonium, and dirty-bomb isotopes like cesium and iridium.
The extent of the black market is unknown, but a steady stream of attempted sales of radioactive materials in recent years suggests smugglers have sometimes crossed borders undetected. Since the formation of a special nuclear police unit in 2005 with U.S. help and funding, 15 investigations have been launched in Georgia and dozens of people arrested.
Six of the investigations were disclosed publicly for the first time to The Associated Press by Georgian authorities. Officials with the U.S. government and the International Atomic Energy Agency declined to comment on the individual investigations, but President Barack Obama noted in a speech earlier this year that countries like Georgia and Moldova have seized highly enriched uranium from smugglers. An IAEA official, who spoke anonymously because he was not authorized to comment, said the agency is concerned smuggling is still occurring in Georgia.
Four of the previously undisclosed cases, and a fifth -- an arrest in neighboring Turkey announced by officials there -- occurred this year. One from last year involved enough cesium-137 to make a deadly dirty bomb, officials said.
Also, Georgian officials see links between two older cases involving highly enriched uranium, which in sufficient quantity can be used to make a nuclear bomb. The AP's interviews with the two imprisoned smugglers in one case suggested that the porous borders and the poverty of the region contributed to the problem.
The arrests in the casino resort of Batumi stand out for two reasons: They suggest there are real buyers -- many of the other investigations involved stings with undercover police acting as buyers. And they suggest that buyers are interested in material that can be used to make a nuclear weapon.
"Real buyers are rare in nuclear smuggling cases, and raise real risks," said nuclear nonproliferation specialist Matthew Bunn, who runs Harvard's Project on Managing the Atom. "They suggest someone is actively seeking to buy material for a clandestine bomb."
The request for uranium raises a particularly troubling question.
"There's no plausible reason for looking for black-market uranium other than for nuclear weapons-- or profit, by selling to people who are looking to make nuclear weapons," said Bunn.
Georgia's proximity to the large stockpiles of Cold War-era nuclear material, its position along trade routes to Asia and Europe, the roughly 225 miles (360 kilometers) of unsecured borders of its two breakaway republics, South Ossetia and Abkhazia, and the poverty of the region may explain why the nation of 4.5 million has become a transit point for nuclear material. Georgian officials say the radioactive material in the five new cases this year all transited through Abkhazia, which borders on Russia and has Russian troops stationed on its territory.
Abkhazia's foreign ministry said it has no information about the Georgian allegations and would not comment, but in the past it has denied Georgian allegations.
Russia maintains that it has secured its radioactive material -- including bomb-grade uranium and plutonium -- and that Georgia has exaggerated the risk because of political tension with Moscow. But while the vast majority of the former Soviet Union's nuclear arsenal and radioactive material has been secured, U.S. officials say that some material in the region remains loose.
"Without a doubt, we are aware and have been over the last several years that not all nuclear material is accounted for," says Simon Limage, deputy assistant secretary for non-proliferation programs at the U.S. State Department. "It is true that a portion that we are concerned about continues to be outside of regulatory control."