One Nation senator Pauline Hanson says Wikileaks founder Julian Assange should be freed, and has likened his plight to that of Australian bushranger Ned Kelly.

In a letter addressed to Prime Minister Malcolm Turnbull, Senator Hanson urged him to begin a multilateral process bringing all Australian political parties together to support Mr Assange.

"Australia has a long and proud history of anti-establishment folk heroes," she said in the letter.

"One only needs to look at the case of Ned Kelly to see this is true.

"Ned Kelly faced government oppression and corruption and was eventually shot and hung.

"I don't think the people of Australia want to see another potential folk hero hung out to dry."

Senator Hanson's push to free Mr Assange has the support of Aboriginal leader Noel Pearson, who wrote in a column for the Daily Telegraph that she "shone an important light" on selective standards of "many Australians".

"Some actions by Assange and WikiLeaks were wrong, such as exposing personal details of innocent or politically unimportant individuals," Mr Pearson said.

"But the released information about wrongdoing by governments is so important that Assange's services to freedom and democracy warrant a pardon, regardless of his mistakes and unrelated allegations — which should be dealt with seriously but separately."

WikiLeaks 'the true fourth pillar of democracy'

Mr Assange, who has published leaked documents ranging from secret US diplomatic cables to Hillary Clinton's campaign chair's emails, has been living in the Ecuadorian embassy in London for four years.

A request was made for the 45-year-old's extradition to Sweden over allegations he committed rape in 2010, but the Australian has refused to go, saying he fears extradition to the United States where a criminal investigation into WikiLeaks has been ongoing since 2010.

Senator Hanson said it is her understanding Mr Assange "has always been prepared" to face allegations in Sweden, if it were not for the "very real threat" of extradition to the US.

"In Australia and under Australian law we believe that a person is innocent until proven guilty," she said.

"In a time when the media cannot be trusted … it is now the work of people like Mr Assange that is so integral to the healthy functioning of our democracy.

"It is organisations such as Wikileaks that are now the true fourth pillar of democracy."