Edward Snowden says he repeatedly raised constitutional concerns about National Security Agency surveillance internally, but an NSA search turned up a single email in which Snowden gently asks for “clarification” on a technical legal question about training materials, agency officials said Thursday.

Snowden, a former NSA systems administrator whose leaks have exposed some of the agency’s most sensitive spying operations, called himself a patriot in an interview this week with NBC News’ Brian Williams. He said he felt he had no choice but to expose what he considered illegal NSA surveillance by leaking secret details to journalists.

NSA officials have said he gained access to some 1.7 million classified documents, though it’s not clear how many he removed from the Hawaii facility where he worked as a contractor.

Asked by Williams whether he first raised his qualms with his bosses, he said, “I reported that there were real problems with the way the NSA was interpreting its legal authorities.”

On Thursday, NSA released the email they said Snowden appeared to be referring to, which the agency says is the only communication from Snowden it could find raising any concerns. It was dated April 8, 2013, three months after Snowden first reached out to journalists anonymously. Former NSA chief Gen. Keith Alexander said the agency could find no one to whom Snowden voiced concerns verbally either.

In the email to NSA’s general counsel’s office, Snowden questions an NSA document showing the hierarchy of governing authorities, which appeared to put executive orders on par with federal statutes.

“I’m not entirely certain, but this does not seem correct, as it seems to imply executive orders have the same precedence as law,” Snowden said in the email. “Could you please clarify?”

An unidentified NSA lawyer began his reply, “Hello, Ed,” and told Snowden he was correct: Executive orders cannot override federal law.

In an email to The Washington Post, Snowden called the official release of the email “incomplete,” the newspaper reported late Thursday.

Snowden said it did not include his correspondence with NSA compliance officials and concerns he had raised about “indefensible collection activities.” He repeated claims that he had shown colleagues “direct evidence” of programs that they agreed were unconstitutional, the newspaper said.

“If the White House is interested in the whole truth, rather than the NSA’s clearly tailored and incomplete leak today for a political advantage, it will require the NSA to ask my former colleagues, management and the senior leadership team about whether I, at any time, raised concerns about the NSA’s improper and at times unconstitutional surveillance activities,” Snowden wrote in response to questions from the Post. “It will not take long to receive an answer.”

Snowden told the Post in December that he raised his concerns face to face with colleagues and supervisors for more than six months. Beginning in October 2012, he said, he brought his concerns about widespread agency surveillance to two superiors in the NSA’s Technology Directorate and two in the NSA Threat Operations Center’s regional base in Hawaii, the newspaper said Thursday.

In the NBC interview — conducted in Moscow, where Snowden now lives outside the reach of pending U.S. criminal charges — Snowden said the reply he got to his email was “more or less, in bureaucratic language, ‘You should stop asking questions.'”

In fact, the lawyer’s email to him concludes, “Please give me a call if you would like to discuss further.”

No specific surveillance program was discussed in the email.

Even if Snowden had complained in detail about the programs he leaked, it’s far from clear that anything significant would have happened. The programs had been blessed by congressional oversight committees, deemed legal by executive branch lawyers and were widely supported in the NSA. The Obama administration changed them after public outcry as a result of the classified material Snowden took and gave to journalists.

But U.S. officials say Snowden’s assertions that he repeatedly tried to raise concerns internally before opting to leak are not accurate.

“There were and there are numerous avenues that Mr. Snowden could have used to raise other concerns or whistle-blower allegations,” White House spokesman Jay Carney said Thursday. “The appropriate authorities have searched for additional indications of outreach from Mr. Snowden in those areas and to date have not found any engagements related to his claims.”

Snowden also claimed he was trained as an undercover spy, an allegation that national security adviser Susan Rice denied.

American Civil Liberties Union lawyer Ben Wizner, Snowden’s legal adviser, called the email issue “a red herring,” and insisted Snowden “raised many complaints over many channels.”

He added, “The problem was not some unknown and isolated instance of misconduct. The problem was that an entire system of mass surveillance had been deployed — and deemed legal — without the knowledge or consent of the public.”

(AP)