Julian Assange tried to contact Hillary Clinton and the White House when he realised that unredacted US diplomatic cables given to WikiLeaks were about to be dumped on the internet, his lawyer has told his London extradition hearing.

Key points: US authorities say the release of unredacted diplomatic cables have put people at risk of torture, abuse or death

US authorities say the release of unredacted diplomatic cables have put people at risk of torture, abuse or death But Julian Assange's lawyer says it was a "lie" that the Wikileaks founder knowingly put lives in danger

But Julian Assange's lawyer says it was a "lie" that the Wikileaks founder knowingly put lives in danger The lawyer said Assange rang the White House to try and speak with Hillary Clinton, then the secretary of state

Assange is being sought by the United States on 17 counts of espionage and one charge of conspiring to commit computer intrusion, having allegedly conspired with Chelsea Manning to leak hundreds of thousands of secret documents almost a decade ago.

The lawyer representing the United States has told the hearing that Assange, 48, was wanted for crimes that had endangered people in Iraq, Iran and Afghanistan who had helped the West, some of whom later disappeared.

US authorities say his actions in recklessly publishing unredacted classified diplomatic cables put informants, dissidents, journalists and human rights activists at risk of torture, abuse or death.

Outlining part of his defence, Assange's lawyer Mark Summers said allegations that he had helped Manning to break a government password, had encouraged the theft of secret data and knowingly put lives in danger were "lies, lies and more lies".

He told London's Woolwich Crown Court that WikiLeaks had received documents from Ms Manning in April 2010.

He then made a deal with a number of newspapers, including the New York Times, Britain's Guardian and Germany's Der Spiegel, to begin releasing redacted parts of the 250,000 cables in November that year.

A witness from Der Spiegel said the US State Department had been involved in suggesting redactions in conference calls, Summers said.

However, a password that allowed access to the full unredacted material on WikiLeaks' servers was published in a book by Guardian reporters about WikiLeaks in February 2011.

A spokesman for the Guardian said the authors were told the password was temporary and the book contained no details about the whereabouts of the files.

In 2011, the newspaper rejected WikiLeaks allegations it was responsible for the leak and said two versions of the cables database had been posted on a file-sharing network using the same password.

"The unencrypted version of the cables published on the web … was not the one accessed by the Guardian [in 2010]," the newspaper said in September 2011.

In August that year, another German newspaper reported it had discovered the password and it had access to the archive.

Julian Assange's legal team denies he knowingly put lives in danger. ( AP: Elizabeth Cook/PA )

Assange told to call back 'in a couple of hours'

Mr Summers said Assange attempted to warn the US Government, calling the White House and attempting to speak to Ms Clinton, then-secretary of state, saying "unless we do something, people's lives are put at risk".

Mr Summers said the State Department had responded by suggesting that Assange call back "in a couple of hours".

The United States asked the United Kingdom to extradite Assange last year after he was pulled from the Ecuador embassy in London, where he had spent seven years holed up avoiding extradition to Sweden over sex crime allegations which have since been dropped.

Supporters for Julian Assange have been waiting outside the courts in London during his extradition hearing. ( ABC News: Tim Stevens )

Assange has served a prison sentence in Britain for skipping bail and remains jailed pending the US extradition request

Supporters hail Assange as an anti-establishment hero who revealed governments' abuses of power, and argue the action against him is a dangerous infringement of journalists' rights.

Critics cast him as a dangerous enemy of the state who has undermined Western security.

Reuters