In March 2003, Russian agents swooped down on a South Korean delegation at the airport here, about 750 miles east of Moscow, as the group prepared to leave after a week at a state research institute. A search of the four visitors' bags produced more than 500 pages of technical material and several CD-ROMs from the Institute for Metals Superplasticity Problems, a research facility that was once part of the Soviet Union's military industrial complex.

A local mechanical engineer looked over the printed materials, an Ufa court was later told, and said the South Koreans were making off with state secrets. A March 2005 memo written by an officer in the Federal Security Service, or FSB, the KGB's domestic successor, was more explicit: The institute's director, Oscar Kaibyshev, was turning over information that could be used in the manufacture of missiles and other weapons.

This March, prosecutors indicted Kaibyshev, 66, contending that information in the Koreans' baggage on how to strengthen materials was "dual-use" technology that could be used for civilian or military applications and that its export was subject to mandatory state controls. He was also charged with embezzlement, abuse of office and forgery.

In interviews at his home here, Kaibyshev denied all the charges. "Only scientifically illiterate people would say we are transferring a military technology," he said.

He is the latest of a string of Russian scientists indicted for exporting technology or conducting research for foreign entities. Scientists and human rights analysts say the evidence is flimsy or nonexistent; the technology in question is not classified, they argue. The cases, about 10 of which have attracted wide publicity in Russia, highlight the powers that the FSB continues to exercise, they say, and often proceed without due process.

The prosecutions could harm the Russian economy by crimping foreign sales of advanced technology, developed for military use during the Cold War but now in demand by civilian industries. The Ufa institute has lost nearly all of its international contracts, worth about $1 million annually, as a result of the Kaibyshev case and now largely depends on the state for survival.

Two special panels at the Russian Academy of Sciences have found that none of the information Kaibyshev gave to the South Koreans was subject to export controls. It had long been in the public domain, they concluded.

Moreover, some of the experts the FSB used to justify its prosecution of Kaibyshev either appear to be unqualified to assess the technology or are his business rivals. The probe was also marred by the conviction of an FSB officer on a charge of stealing about $70,000 from the institute's safe.

"It became increasingly clear that the FSB was acting in bad faith in these investigations, seeking to have the defendants convicted while ignoring facts that could exonerate them," Human Rights Watch, in an October 2003 report titled "Spy Mania," said of the string of cases against scientists. Russian scientists have said the Kaibyshev case conforms to that pattern.

The FSB declined to comment for this article.

A Respected Researcher

Kaibyshev was once a pillar of the Communist establishment, serving in the Soviet parliament in the 1980s. He was a scientific troubleshooter for the military and the space program, he said, working on metal fatigue in submarine-based nuclear missiles and helping solve metal problems in the Soviet equivalent of the U.S. space shuttle program.

In 1985, his growing prestige led to his appointment as head of the IMSP, the first facility in the world exclusively devoted to superplasticity, a physical property, usually of a metal or alloy, that allows it to stretch while holding or increasing strength. He published a book on the subject in the United States this spring and holds several international patents on the technology.

The collapse of the Soviet Union devastated the country's research centers, leaving many without funding. "This is the point where a different life begins," Kaibyshev recalled of the period. "The domestic market for high technology collapsed, and we needed to enter the international market."

Through the 1990s, his institute secured contracts with international firms, including General Electric Co., for which it worked on strengthening metal in aircraft engine parts.

"He is a highly respected scientist," said Kuppuswamy A. Padmanabhan, a physics professor at the University of Hyderabad, India, who has known Kaibyshev since 1989. "Even after the collapse of the U.S.S.R., he saved many posts at his institute by hard work and paid his colleagues a decent salary, which was in sharp contrast with . . . other institutes."

The institute began to work with the South Korean company ASA Co. in 2001, helping it develop a new manufacturing technique for car wheel frames. The delegation that arrived in Ufa in March 2003 included representatives from the Korea Aerospace Research Institute, according to Nam Sung Kang, a director of ASA. The institute reached agreement with them on details and financing for a new series of research projects, Kaibyshev said.

Then the FSB struck, picking up Kaibyshev as he returned home from walking his dog and detaining the Koreans at the airport. "It was a carefully planned interrogation," Kang said.

The planning was less than perfect, however. The mechanical engineer who said the Koreans had state secrets in their suitcases does not speak or read English, according to his personnel file, and the documents were in English. The FSB now appears to have dropped the man as a witness, according to Yuri Gervis, Kaibyshev's attorney.

At the time the engineer was assisting the FSB, he was suing Kaibyshev for co-authorship of a patent and was also involved in a rival start-up, according to court records. The engineer, Rif Baimurzin, lost the patent case last year. He hung up when called by a reporter.

The FSB seized a safe from Kaibyshev's office at the institute that contained three promissory notes, one worth $50,000 and two more worth about 2 million rubles (about $70,000). When Kaibyshev asked for the money back, only the dollar-denominated note was returned. Kaibyshev said an FSB agent warned him not to keep asking about the rest of the money. "We will bury you," he recalled the agent saying.

Kaibyshev contacted his bank, which said the ruble notes had been cashed. Initially, the FSB said Kaibyshev had stolen the notes, Kaibyshev said, but an investigation by the prosecutor's office led to an FSB major who eventually drew a five-year suspended sentence for theft. Despite its power, the FSB does at times get in trouble with the courts; the money was eventually returned.

"It's personal now," said Gervis, the attorney. "The FSB will do everything to keep up face."

Conflicts of Interest

As the investigation of the Korean contracts continued, Kaibyshev appealed to the Russian Academy of Sciences. In the summer of 2003, it supported the scientist's claim that the information was not classified. The Russian Ministry of Economic Development also held a hearing, which largely supported Kaibyshev but raised questions about one shipment of titanium alloy objects. A second, larger panel at the Academy of Sciences heard the case in October 2003 and considered the ministry's concerns. It again found no violations of the law.

The FSB sought out new experts. In a March 2004 report, a St. Petersburg technical firm it had hired said Kaibyshev should have obtained export licenses. In late 2004, the security agency received an even more damning assessment from Salut, a Moscow company that manufactures aircraft engines. Salut's experts concluded that some of the technology in question could help countries build missiles that might "be used for the delivery of weapons of mass destruction," according to their report.

"Missiles?" said Kang, the ASA director, breaking into laughter when asked about that report. "We're not interested. We're just a private business company."

Again, there were questions of conflict of interest. Salut had had a troubled business relationship with Kaibyshev. In 2001, Kaibyshev said, he asked the company to pay for the use of one of his patented technologies. "We had business relations, but not for a long time," said Salut's director, Yuri Yeliseyev.

Salut is also promoting a conference with a Belgian firm this summer on using superplasticity in the manufacture of aircraft engine parts. "If Belgians can sell superplasticity to Russia, they can just as well sell it to anyone, to South Korea," Kaibyshev said. "If the Belgians are ready to export, it means this is public domain."

Kaibyshev is confined to the city of Ufa until his trial and must report to the FSB every day. "They're trying to kill . . . my life's work," he said, "but they'll never succeed. I'll fight them to the end."

Special correspondent Joohee Cho in Seoul contributed to this report.

Oscar Kaibyshev is accused of exporting dual-use technology to South Korea. Critics say the technology was not classified.