Former Liberal prime minister Malcolm Fraser has been remembered as "a giant of Australian politics" and a "great moral compass" following his death early this morning at the age of 84.

"It is with deep sadness that we inform you that after a brief illness, John Malcolm Fraser died peacefully in the early hours of the morning of 20 March, 2015," a statement released by his office said.

"We appreciate that this will be a shock to all who knew and loved him, but ask that the family be left in peace at this difficult time."

Mr Fraser — Australia's 22nd prime minister — was born into a wealthy pastoral family in 1930 and first entered Parliament in 1955 as its youngest MP.

He spent nearly 20 years as a backbencher and in the ministry.

From his first days in politics, Mr Fraser was an advocate of immigration as a means of boosting the population.

As a minister in the Gorton government, he became the first federal politician to use the word "multiculturalism" — an historic break from the Anglocentric past of his own party.

He became opposition leader in 1975, facing off against Gough Whitlam and becoming prime minister in the wake of Mr Whitlam's dismissal.

Mr Fraser's multicultural conviction found shape in immigration policy in the post-Vietnam war push to bring refugees from mainland South East Asia to Australia.

"I believe we had a moral and ethical obligation," Mr Fraser later said.

"If we had taken polls ... I think people would have voted 80, 90 per cent against us but we explained the reasons for it.

"We were also working to get people to understand that the idea and the reality of a multicultural Australia could be an enormous strength to this country, not a weakness.

"There is strength in this kind of diversity so long as we understand what it's about."

After the Whitlam years, there was persistent debate about the new government's legitimacy and Mr Fraser's role.

But he went on to win the next three elections.

In addition to multiculturalism, he embraced Aboriginal land rights, led the Commonwealth push to end Apartheid in South Africa and argued for an independent Zimbabwe.

The nation's finances were managed with traditional conservatism and cutbacks at first but later, the political pressure grew and the purse strings loosened.

However, in 1982 the country was facing recession, drought and social unrest.

After suffering a back problem and being treated in hospital, Mr Fraser called a snap election on the same day Bob Hawke became opposition leader.

But the strategy backfired and Mr Fraser was defeated.

Fraser becomes staunch critic of Liberal Party

Life after the Lodge remained busy for Mr Fraser; he became a key figure in humanitarian and diplomatic circles, and he became a staunch critic of the Liberals under the next Coalition PM, John Howard, speaking out particularly on Indigenous issues, refugees and anti-terrorism laws.

In 1987, he formed CARE Australia as part of the international CARE network of humanitarian aid organisations. He remained chairman until 2002.

For two decades there was largely bipartisan consensus on immigration policy, until that was repudiated by the Howard Government.

The 2001 election completed Mr Fraser's estrangement from the Liberal Party.

It was the year the government sent troops to board the Tampa, a cargo vessel carrying asylum seekers who wanted to come to Australia.

It was the era of Pauline Hanson's One Nation Party, a time when Mr Fraser found fault with politics and politicians from his own side.

"I suppose Pauline Hanson is one answer but she's an excuse really," he said.

"I guess we've got some people in Canberra who believe that what they're doing is right. I believe it is profoundly wrong.

"I think putting the SAS onto the Tampa did more to damage Australia worldwide than any other single act of government."

In November 2006, Mr Fraser established Australians All to promote a more inclusive society through discussion and reform of inequalities and discrimination in law and policy.

By then he had become a staunch critic of asylum seeker policy in the Howard years.

"The party has become a party of fear and of reaction, its conservative and not liberal, it is unrecognisable as liberal," he said.

Mr Fraser seemed to have more in common with his former political rivals than with his own party, joining Labor PMs past and present for the apology to the Stolen Generations.

It had been his ambition that Australia's population reach 25 million people in his lifetime.

But as the shadows lengthened, Mr Fraser found himself at odds, again, with the Coalition he had once led.

After the election of Tony Abbott as leader in 2009 he resigned from the Liberal Party — after more than six decades — and when Mr Abbott began turning back the boat people Mr Fraser did nothing to hide his contempt.

"You know it's ironic that Pauline Hansen was saying boat people should be sent back. Not too long afterwards that's just what the Government does," he said.

Just last month Mr Fraser launched a scathing attack on Mr Abbott over the Government's treatment of the Human Rights Commission and, in particular, president Gillian Triggs following The Forgotten Children report.

"If the Government had wanted to handle the matter sensibly, they would have said they recognise there have been abuses," Mr Fraser said.

Mr Fraser will be remembered for infamous quotes such as, "Life wasn't meant to be easy" and being called "Kerr's cur" by Mr Whitlam, when Mr Whitlam was sacked by governor-general Sir John Kerr on November 11, 1975.

Mr Fraser took the quote "Life wasn't meant to be easy" from the George Bernard Shaw play Back to Methuselah: "Life wasn't meant to be easy, my child; but take courage: it can be delightful."

Mr Fraser is survived by his wife and four children.
(ABC)