Screen capture by CNET/"Last Week Tonight with John Oliver"

Former US National Security Agency analyst Edward Snowden has delivered a damning verdict on Australia's new data retention laws, saying they are "radical" and "dangerous," telling Australians "regardless of whether or not you're doing anything wrong, you are being watched."

The former NSA contractor made the comments on Friday during Melbourne's Progress 2015 conference, appearing via video link from Moscow. Snowden has been holed up in the Russian capital since 2013 when he released a huge cache of classified NSA documents to the Guardian, documenting what he alleged amounted to state-sanctioned spying on US citizens.

Snowden has now taken his crusade against Government surveillance to Australia, saying the local example is similar to data retention programs in the UK and part of a much larger global trend towards mass surveillance. Snowden argued that both UK and Australian Governments were enacting a form of "pre-criminal investigation".

They are watching everybody all the time. They're collecting information and they're just putting it in piles that they can then search through not only locally, not only within Australia, but they can then share this with foreign intelligence services, such as the United States national security, the United Kingdom's government communications headquarters, and they can troll through these communications in the same way and this often happens beyond any sort of court oversight. The ultimate result there is the fact that regardless of whether or not you're doing anything wrong, you are being watched.

While Australia's data retention legislation has been drafted to include safeguards for journalists -- a move made by the Federal Government after increased pressure from the Federal Opposition and various media and civil liberties groups -- Snowden contested these protections do not go far enough to protect journalists and their sources.

"Under these mandatory metadata programs that were passed in Australia, you can immediately see who journalists are contacting, from which you can derive who their sources are," he said.

"If there is, for example, a leak that happens in the Australian intelligence services that reveals to the newspapers that these services have been abusing their powers and the Government can simply go into their mass collection of everyone's communications, regardless of whether they are suspected of any crime or whether they're going about their daily business, it is all there."

Snowden argued the purpose of a free press is to champion the public interest and to "hold the most powerful officials in our society to the account of the law" but that this task is "is traditionally quite difficult to do when operations are occurring behind a veil of secrecy".

The comments from Snowden echoed similar calls from civil liberties groups and digital rights advocates who lobbied extensively against the Government's data retention bill in the months before it passed. Despite opposition from these groups and from the public, the legislation passed with bipartisan support in March.

But Snowden has argued against the passage of these laws, saying retention of metadata is "dangerous" and "a radical departure from the traditional operations of liberal society".

"[These are] not things that governments have ever traditionally been in power to claim for themselves as authorities," he said.