The former head of the Australian security agency was seen as a political hero by many Australians and was a frequent visitor to the country.
His death has reignited a debate about the role of spies in Australia and its relationship with Washington.
Former intelligence officer Mark Felt, who now lives in Perth, said that the killing of Mr Felt could have an impact on the country’s relations with Washington, saying that it “could potentially be the start of a change”.
Mr Fears, a former director of the National Security Agency (NSA), was a friend of the prime minister, Malcolm Turnbull, and was an influential figure in the government’s foreign policy.
He was also a supporter of former US President Barack Obama’s decision to allow Australian troops to leave Afghanistan.
Mr Fearing had spent a lot of time in Australia, spending time with both Mr Turnbull and former President John Howard, the former prime minister said.
“He was a very good man.
He had a good heart.
He really cared about the country, he had a very big heart, he was a really good man,” Mr Howard said.
Australian spies and the Bush administration Mr Felfelt was seen by many as a hero by Australians who admired his courage, integrity and intelligence.
He became a close confidant of then-Prime Minister John Howard and his national security adviser, Peter Clarke, and served as a national security liaison between Australia and the US.
He also became an adviser to the US ambassador to Australia in Canberra, John Cusack.
But Mr Fels actions were controversial in Australia.
Former US Ambassador to Australia John Felt (left), former US president Barack Obama and former prime ministers John Howard (centre) and John Howard.
In 2002, the Australian government revealed the identity of one of its spies, Mark Fels, who worked for the NSA.
Australian Prime Minister Kevin Rudd said at the time that he did not believe Mr Fessel had been targeted because of his relationship with the Australian Government.
But he later said that Mr Flesons death had “no bearing” on Australia’s relations.
“There is no evidence of any threat to the Australian people, or any evidence of Australians being targeted in this way,” Mr Rudd said in a statement in May 2002.
In the weeks before Mr Flemings death, he visited Canberra, Sydney and Melbourne, according to a report by ABC Radio Canberra’s Stephen FitzSimons.
But his last post-mortem examination showed no evidence that he had been killed by a bomb, the ABC reported.
The ABC reported that he was “travelled from Australia to New York, Chicago, Washington, D.C., and then back to Australia again” and that he died of “an undetermined cause”.
The Australian Government said that in addition to being a spy, Mr Flevins role was “to provide the intelligence that would enable the United States to gain access to Australian assets in a timely manner”.