It could be the plot of a Cold War thriller: A Soviet mole burrows into America's top biodefense lab and steals strains of the deadly viruses that cause Rift Valley and Lassa fevers.
He ships the killer microbes back to Moscow in the bags of Aeroflot pilots, who turn them over to a super-secret arm of the KGB that plots bioterror attacks.
A chilling tale of fictional intrigue? Some biowarfare experts think it actually happened at Fort Detrick in the 1980s, and they say there is evidence to support their suspicions.
Alexander Y. Kouzminov, a biophysicist who says he once worked for the KGB, first made the allegation last year in a book, Biological Espionage: Special Operations of the Soviet and Russian Foreign Intelligence Services in the West.
Biowarfare experts dismissed the memoir at first, largely because Kouzminov also claimed that a series of contemporary disease outbreaks resulted from the release of germ weapons.
But in recent weeks, another former Soviet scientist told The Sun that his lab routinely received dangerous pathogens and other materials from Western labs through a clandestine channel like the one Kouzminov described.
Also, a U.S. arms control specialist says he has independent evidence of a Soviet spy at Fort Detrick. Although not definitive, their statements buttress Kouzminov's allegations about the Frederick military installation.
Experts worry that the United States' huge $7-billion-a-year biological defense effort will increase the odds of bioterrorism - by generating dangerous new microbes and scientific knowledge that could be diverted or stolen.
The FBI declined to comment on the possibility of Soviet spying at Fort Detrick in the 1980s. However, if an agent once penetrated America's top biodefense lab, biowarfare experts say, the incident would show how difficult preventing such losses can be.
The Detrick agent, Kouzminov wrote, clandestinely "gained information" on experiments with Rift Valley and Lassa fevers, hemorrhagic diseases that can drown a victim in his own body fluid, as well as the bacterium that causes tularemia, which can cause diarrhea, vomiting and pneumonia.
KGB officials also sought a sample of the U.S. smallpox vaccine, although Kouzminov does not say whether they obtained it. Soviet defectors have reported that in the 1970s and 1980s, the U.S.S.R. was trying to develop vaccine-resistant organisms capable of defeating U.S. biowarfare defenses.
Serguei Popov, a scientist once based in a Soviet bioweapons lab in Obolensk, south of Moscow, said that by the early 1980s his colleagues had obtained at least two strains of anthrax commonly studied in Detrick and affiliated labs. They included the Ames strain, first identified at Detrick in the early 1980s. It became the standard used for testing U.S. military vaccines, and it was the strain contained in the 2001 anthrax letters that killed five people and infected 23 in the U.S.
Popov, now at the National Center for Biodefense and Infectious Disease at George Mason University in Fairfax, Va., said Obolensk researchers could easily obtain organisms mentioned in Western research papers.
"If you wanted 'special materials,' you had to fill out a request," he said. "And, essentially, those materials were provided. How and by whom, I can't say."
One colleague, Popov said, used this "special materials" program to obtain a strain of Yersinia pestis, a plague bacterium being studied in a Western lab. But he didn't know whether that particular germ came from Detrick.
There has never been any doubt about Detrick's key role in the history of U.S. biowarfare. Once a sleepy military airfield, the facility was turned into a center for top-secret research into biological weapons in the waning days of World War II.
It remained so until 1969, when President Richard M. Nixon ended development of new U.S. bioweapons, and the military study of lethal organisms shifted to the U.S. Army Medical Research Institute of Infectious Diseases, or USAMRIID.
That agency was founded at Fort Detrick in the late 1960s to conduct defensive biological research. Its scientists developed new vaccines and drugs to treat natural and manmade outbreaks.
Given that change in mission, former Detrick scientists and arms control experts agree that there were no secret, offensive programs at Detrick in the 1980s. In fact, they say there wasn't much secret work at all.
But Kouzminov says the KGB still wanted specific items from Western labs - including Detrick - that were closely held or at least not widely available.
Those included samples of specific disease strains, the growth media used to raise microbes, and vaccines the labs developed. The Soviets also wanted the aerosol powders U.S. scientists used to infect animals with bioagents during drug and vaccine tests.
At least three KGB spies targeted U.S. biodefense efforts in the 1980s, Kouzminov said. But the biophysicist, who worked primarily in Western Europe, offers no details about what the other two did. He wrote that his superiors called "our man at Detrick" their key biological agent.
Kouzminov and the biological moles worked in the KGB's Department 12 of Directorate S, housed in a high-rise building in a forested patch of southern Moscow. The group's mission, he said, was to develop germ weapons and poisons, to steal biodefense secrets and to plot biochemical terror attacks to be launched in the event of war.
The description of Department 12 in Biological Espionage squares with those of other defectors, said Oleg D. Kalugin, a retired KGB major general now living in the U.S.
Raymond Zilinskas, a bioweapons expert with the Monterey Institute of International Studies, and two colleagues wrote a scathing review of Biological Espionage in Nature, a British scientific journal.
The authors challenged Kouzminov's claims that the U.S. is pursuing an offensive bioweapons program. For example, he suggested that the 1993 outbreak of hantavirus in the American Southwest resulted from a U.S. military release of a bioweapon genetically engineered to attack Native Americans. The Nature review called the allegation "bizarre" and "astonishing."
The authors also complained that Kouzminov revealed few real KGB secrets. "It seems surprising," the reviewers wrote, "that an insider can write a book about the special operations of Soviet foreign intelligence services ... and provide so little about their achievements."
But Zilinskas, who is researching a history of the Soviet bioweapons program, told The Sun this month that his sources now say that Soviet intelligence routinely obtained details of work at USAMRIID that went beyond the descriptions in scientific journals.
"It was clear there was somebody at Fort Detrick" who worked for Soviet intelligence, Zilinskas says.
According to Kouzminov's account, the KGB delivered biological materials to Moscow through what was called the VOLNA channel. Aeroflot pilots who were also KGB officers carried these sometimes-lethal microbes to Moscow's Sheremetyevo airport in their personal luggage.
By the late 1980s, Department 12 was receiving about 20 parcels a year through VOLNA from agents in its American section, which included North, Central and South America.
In an e-mail, Kouzminov said he didn't know the identity of the Detrick spy or other details of the USAMRIID espionage. Such knowledge was closely guarded, even within the KGB. Careless comments by his bosses, though, suggested that the agent was a devout Catholic whose work frequently took him to Latin America.
Milton Leitenberg, an arms control expert with the Center for International and Security Studies at the University of Maryland, College Park, investigated the spying claim last year. As far as he can determine, no one fitting Kouzminov's description worked at Detrick in the 1980s.
An FBI spokesman said the agency would not comment on spying allegations.
But William C. Patrick III, a retired Detrick biologist and veteran bioweapons expert, said he has long suspected penetration by Soviet agents.
His suspicions cropped up in the early 1990s, when he debriefed Ken Alibek, who as Kanatjan Alibekov served as the deputy chief of Biopreparat, the leading Soviet bioweapons research agency. Alibek emigrated to the U.S. less than a year after the dissolution of the Soviet Union in December 1991.
As he and Alibek traded stories, Patrick said, both realized that the Soviet and American programs had moved in a curious lock step during the 1950s and '60s.
"Anything we discovered of any import, they would have discovered and would have in their program in six months," Patrick said.
He doesn't doubt that the Soviets kept spying beyond the end of the U.S. offensive program. After his conversations with Alibek, he recalled, "For the next two weeks I tried to think, 'Who the hell are the spies at Detrick?'"
It would have been surprising if the KGB had not kept an eye on Fort Detrick, which was vilified in the Soviet press as a palace of sinister secrets.
Researchers who worked at Detrick at the time say there was no basis for this notoriety. Dr. C. J. Peters, a researcher and administrator at USAMRIID from 1977 to 1992, said a mole at Detrick in those days wouldn't have turned up critical intelligence - or obtained germs - that the KGB couldn't have found elsewhere.
Kouzminov claimed in his book that the KGB targeted "secret" experiments at USAMRIID. But Peters said that almost all the lab's work was published in scholarly journals, and scientists there worked on only two classified projects during that era. In one, scientists screened blood serum from U.S. Special Forces for novel infections. In another, the lab analyzed blood from two elite Soviet commandos.
Still, the Soviets were deeply suspicious of Detrick. Many former Russian bioweapons experts remain so.
Dr. Pyotr Burgasov, a former chief sanitary physician of the Soviet Union, recalled in a 2002 interview with The Sun how he was escorted through Fort Detrick in the late 1960s - and was barred from one building. Detrick officials told him they feared he might contaminate the sterile research animals inside. But 11 years after the U.S.S.R. crumbled, he still didn't buy that explanation. "I am told America shows its research to scientists," he said. "But they showed nothing to me."
Distrust evidently bred cynicism. According to defectors, at the moment Soviet leaders signed the Biological Weapons Convention in 1975, they were pursuing a large-scale clandestine germ weapons program. After the deception was exposed, President Boris N. Yeltsin ordered a halt to offensive research in 1992.
Kouzminov, in a series of e-mails, defended his book against critics, saying that his aim was to raise an alarm about the "possibility" that several nations - including the U.S. - are conducting offensive bioweapons research. He also proposes the creation of an International Biological Security Agency, modeled on the International Atomic Energy Agency, to prevent proliferation.
Russia's biodefense establishment might have a vested interest in raising fears about U.S. intentions, some experts think. If Russia's leaders feel threatened, one said, they could increase spending on biodefense and intelligence agencies - institutions that have struggled for money since the end of the Cold War.
The FBI also questions whether Biological Espionage has an ulterior purpose. Agency spokesman William D. Carter said in a statement that "there is no way to discount that this book (like other books by former intel officers who seem to have no problem moving around, including into and out of Russia) is not part of a disinformation campaign by the Russians."
Kouzminov, who left Russia with his family in 1994, called the FBI's disinformation comment "rubbish," a reflection of Cold War thinking. "I have written this book purely from my heart," he wrote. "I was alone in this, without any group ... behind my back."