A US House of Representatives intelligence committee report has called Edward Snowden, the National Security Agency (NSA) leaker, a "serial exaggerator and fabricator" who does not fit the profile of a whistleblower.
The Republican-led committee released a three-page unclassified summary of its two-year bipartisan examination on Thursday, which details how Snowden was able to remove the documents from secure NSA networks, what information the documents contained, and the damage their removal caused to US national security.
Adam Schiff, a Democratic member of the House intelligence committee, said the investigation revealed that the vast majority of what Snowden took had nothing to do with American privacy.
"The majority of what he took has to do with military secrets and defence secrets," Schiff said in an interview for C-SPAN's Newsmakers.
''I think that's very much at odds with the narrative that he wants to tell that he is a whistleblower."
In a series of tweets, Snowden, 33, dismissed the House committee's report as "artlessly distorted" and a "serious act of bad faith".
Snowden was an NSA contract employee when he took the documents and leaked them to journalists who revealed extensive domestic surveillance programmes begun in the aftermath of the 9/11 attacks.
Snowden fled to Hong Kong, then Russia, to avoid prosecution and now wants a presidential pardon because he says he helped his country by revealing secret domestic surveillance programmes.
The programmes collected the telephone metadata records of millions of Americans and examined emails from overseas.
Snowden's attorney also criticised the House committee's report, which was released on the eve of the opening of the film Snowden on Thursday.
Snowden's revelations about the agency's bulk collection of millions of Americans' phone records set off a fierce debate that pitted civil libertarians concerned about privacy against more politicians fearful about losing tools to combat terrorism.
Devin Nunes, chairman of the House intelligence committee, said Snowden betrayed his colleagues and his country.
"He put our service members and the American people at risk after perceived slights by his superiors," Nunes said in a statement.
"In light of his long list of exaggerations and outright fabrications detailed in this report, no one should take him at his word. I look forward to his eventual return to the United States, where he will face justice for his damaging crimes."
Snowden insists he has not shared the full cache of 1.5 million classified documents with anyone. However, the report notes that in June, the deputy chairman of the Russian parliament's defence and security committee publicly conceded that "Snowden did share intelligence" with his government.
Ben Wizner, Snowden's lawyer at the American Civil Liberties Union (ACLU), said the committee' report was an attempt to discredit a "genuine American hero".
"After years of investigation, the committee still can't point to any remotely credible evidence that Snowden's disclosures caused harm," Wizner said.
The committee, on the other hand, called Snowden a "disgruntled employee who had frequent conflicts with his managers".
According to the committee, Snowden began mass downloads of classified material two weeks after he was reprimanded for engaging in a spat with NSA managers.
The committee also described Snowden as a "serial exaggerator and fabricator".
"A close review of Snowden's official employment records and submissions reveals a pattern of intentional lying," the report said.
"He claimed to have left Army basic training because of broken legs when in fact he washed out because of shin splints. He claimed to have obtained a high school degree equivalent when in fact he never did."
The report said Snowden claimed to have worked for the CIA as a senior adviser, when he was a computer technician.
"He also doctored his performance evaluations and obtained new positions at NSA by exaggerating his resume and stealing the answers to an employment test," the report said.
Speaking by video link from Moscow, Snowden said on Wednesday that whistleblowing "is democracy's safeguard of last resort, the one on which we rely when all other checks and balances have failed and the public has no idea what's going on behind closed doors".
He addressed a New York City news conference where advocates from the ACLU, Human Rights Watch and Amnesty International announced an online petition drive to urge Obama to pardon Snowden before he leaves office.
The Obama administration has urged Snowden to return to the US and face trial.