The National Security Agency (NSA) says it has found only one e-mail from Edward Snowden relative to the former U.S. intelligence contractor's claim that he'd reported "real problems" about how the NSA interprets its legal authority.
The e-mail, released on May 29, does not mention surveillance of U.S. citizens under the program Snowden later exposed.
It is dated April 5, 2013 -- more than a month before he leaked classified documents but after he first anonymously contacted journalists.
It shows Snowden asked for "clarification" about an NSA document listing a hierarchy of governing authorities.
An unidentified NSA lawyer replied three days later, saying Snowden was correct that executive orders cannot override federal law.
The lawyer also told Snowden to telephone if he had further concerns.
Former NSA chief Keith Alexander said the agency could not find anyone to whom Snowden voiced concerns orally.
With reporting by AP