Grand jury transcripts released Thursday from the biggest espionage case of the Cold War raise questions about whether Ethel Rosenberg was convicted and executed based on perjured prosecution testimony.

The Rosenbergs were convicted of passing nuclear weapons secrets to the Soviet Union and were executed in 1953. Since then, decrypted Soviet cables have appeared to confirm that Julius Rosenberg was a spy, but doubts have remained about Ethel Rosenberg’s role.

At the Rosenbergs’ trial, the key testimony against Ethel Rosenberg came from her brother and sister-in-law, David and Ruth Greenglass.

They testified that Ethel Rosenberg had typed stolen atomic secrets from notes provided by David Greenglass. The testimony provided the direct involvement the jury needed to convict and that the judge in the case needed to sentence Ethel Rosenberg to death.

In fact, in her grand jury testimony, Ruth Greenglass says that she herself wrote out the secrets in longhand. That testimony is consistent with the subsequently decrypted Soviet cables from the time in which the Soviets describe material received from the Rosenbergs as being in longhand.

The grand jury testimony from Ruth Greenglass confirms that the trial testimony about typing is a complete fabrication, said Georgetown University law professor David Vladeck, part of the team of lawyers and historians who succeeded in gaining public release of the transcripts.

The government also had evidence that the Rosenberg ring gave the Soviets secrets about airborne radar, land-based radar, analog computers used for guiding anti-aircraft weapons and information for the first designs of U.S. jet engines, said Steve Usdin, an author who helped win release of the grand jury material.