The mass disclosure of the Edward Snowden files has "done considerable damage" to national security in a number of countries, a former terror laws watchdog has said.
Lord Carlile's comments come two years after the first press reports based on files leaked by Snowden, an ex-National Security Agency (NSA) worker.
The Lib Dem peer, a former independent reviewer of terrorism legislation, said: "I am absolutely certain that the way in which the Snowden cache was revealed has done considerable damage to the national security of numerous countries.
"I regret very much that so much Snowden material has appeared on the internet.
"If Edward Snowden is a legitimate whistleblower, and he may be, I don't know, but if he were a legitimate whistleblower, there are different ways in which it could have been done."
Referring to claims that Snowden did not read all of the documents he disclosed, Lord Carlile said: "He had no idea whether he was doing damage to people or not."
He added: "My view is that the media should have been much more cautious in the way the revelations were made.
"I do not believe the story would have been diluted one jot by selective publication of one or two hundred publications.
"I regret very much that it happened in that way.
"I absolutely support press freedom, I think there may well have been a very strong public interest in some of the things Snowden revealed being published, but it should have been done differently."
Last week former Guardian editor Alan Rusbridger told Press Gazette he had no regrets about the Snowden stories and that critics were never able to say which particular story damaged national security,
Lord Carlile's comments echo repeated warnings by senior police and intelligence officials that the disclosures damaged their capabilities.
Snowden (pictured above: The Guardian) triggered a wave of controversy when he leaked tens of thousands of documents about surveillance programmes run by the NSA and foreign counterparts, including Britain's GCHQ, in 2013.
He fled to Hong Kong where he met journalists working for The Guardian, as well as documentary film-maker Laura Poitras, to co-ordinate a series of articles that would expose mass surveillance programmes such as the NSA's Prism and GCHQ's Tempora, which involve "hoovering up" vast volumes of private communications.
Once Snowden's identity was out, he fled to Russia, where he remains wanted by the US authorities.
The first article based on the documents appeared on June 5 2013.
Earlier this week Snowden, 31, said becoming an "international fugitive" has been worth it because of "benefits" it has brought the public.
He insisted progress had been made in the last two years since then, and added: "The difference is that you get a different quality of government when they are accountable to the public.
"It has been incredibly rewarding, incredibly gratifying.
"Although I can no longer see my family, I can no longer live in my home, I can no longer work with colleagues I respect, the things I've received personally, and we've all benefited from publicly, make it all worth it."
Amnesty International said a poll of 1,552 adults in Britain found that 56 per cent of respondents believed that he should have revealed classified information.