[8] ASIO is the statutory body established and regulated under the Australian Security Intelligence Organisation Act 1979, responsible to the Parliament of Australia through the Attorney-General.

[11][12] Furthermore, ASIO has undergone a period of rapid growth with some 70% of its officers having joined since 2002, leading to what Paul O'Sullivan, Director-General of Security from 2005 to 2009, called 'an experience gap'.

Furthermore, the Attorney-General issues guidelines with respect to the conduct of ASIO investigations relating to politically motivated violence and its functions of obtaining intelligence relevant to security.

[18] During World War II, Commonwealth Security Service was formed in 1941 to investigate organisations and individuals considered likely to be subversive or actively opposed to national interests; to investigate espionage and sabotage; to vet defence force personnel and workers in defence-related industries; to control the issue of passports and visas; and was responsible for the security of airports and wharves, and factories engaged in manufacture of munitions and other items necessary for Australia’s war effort.

During World War II, Reed conducted an inquiry into Wake's performance as a security officer and found that he was competent and innocent of the charges laid by the Army's commander-in-chief, General Thomas Blamey.

Following the end of World War II, the joint United States-UK Venona project uncovered sensitive British and Australian government data being transmitted through Soviet diplomatic channels.

Historian Robert Manne describes this early relationship as "special, almost filial" and continues "ASIO's trust in the British counter-intelligence service appears to have been near-perfect".

[23] The Labor Government was defeated at the December 1949 federal election, and in March 1950 the new prime minister, Robert Menzies, appointed the Deputy Director of Military Intelligence, Charles Spry, as the second Director-General of Security, commencing on 9 July 1950.

[25] Among the prime suspects of the investigations were Wally Clayton, a prominent member of the Australian Communist Party,[26] and two diplomats with the Department of External Affairs, Jim Hill and Ian Milner.

An ASIO field officer identified Petrov as a possible 'legal', an agent of the Soviet Ministry of State Security (MGB, a forerunner to the KGB) operating under diplomatic immunity.

Petrov was spirited to a safe house by ASIO officers, but his disappearance and the seeming reluctance of Australian authorities to search for him made the Soviets increasingly suspicious.

However, ASIO was in communication with the pilot and learned through relayed conversations with a flight attendant that if Evdokia spoke to her husband she might consider seeking asylum in Australia.

Evatt, the leader of the Labor Party at the time, accused Prime Minister Robert Menzies of arranging the Petrov defection to discredit him.

[23] In fact, when Brigadier Spry retired, the Deputy Director of the CIA sent the following tribute: ASIO's counter-intelligence successes continued throughout the Cold War.

[citation needed] In 2012 it was reported that ASIO had been monitoring the actions of Australians protesting against the coal industry, and was increasing its efforts from previous years.

[34] Australian Greens party leader Bob Brown described ASIO monitoring environmentalists as a "political weapon" used by the Government for the benefit of "foreign-owned mining corporations".

[35][36] Nicola Roxon, the Attorney-General of Australia, blocked Chinese, state-owned company Huawei from seeking a supply contract for the National Broadband Network, on the advice of the ASIO.

[40] Uren, former Assistant Secretary responsible for the Asia section of the Office of National Assessments, was found to have removed documents pertaining to Chinese intelligence operations in Australia, and kept them in his apartment.

[40] Yan was suspected of undertaking influence operations on behalf of the Chinese Communist Party, and introducing Colonel Liu Chaoying, a military intelligence officer, to Australian contacts.

In a secret supplementary report, much of which remains classified, Hope indicated his belief that ASIO's past conduct was the result of its infiltration by a hostile foreign intelligence agency.

In the report concluded in 1979, Justice Hope designated ASIO as the agency responsible for national threat assessments in terrorism and politically motivated violence.

Following the publicity surrounding the expulsion of Valery Ivanov, First Secretary at the Soviet Embassy in Canberra, the Government established a Royal Commission to review the activities of Australian security and intelligence agencies.

In early 1992, Prime Minister Paul Keating commissioned a review "of the overall impact of changes in international circumstances on the roles and priorities of the Australian intelligence agencies".

The Committee concluded that "the total package of information available to the Australian community about ASIO's operations exceeds that available to citizens in other countries about their domestic intelligence agencies."

Former police officer Terry Griffiths, who was injured in the explosion, provided some evidence that suggested ASIO might have orchestrated the bombing or been aware of the possibility and allowed it to proceed.

The couple subsequently sought damages and the embarrassing incident was settled out of court in late 2005, with all material relating to the case being declared strictly confidential.

Parkin was detained in Melbourne and held in custody for five days before being escorted under guard to Los Angeles, where he was informed that he was required to pay the Australian Government A$11,700 for the cost of his detention and removal.

The Attorney-General at that time, Philip Ruddock, refused to explain the reasons for Parkin's removal,[60] leading to speculation that ASIO had acted under pressure from the United States.

[62] O'Sullivan refused to answer questions before a later Senate committee hearing[63] after his legal counsel told the Federal Court that ASIO did not necessarily base its assessment solely on Parkin's activities in Australia.

[66] ASIO and the Australian Federal Police had investigated ul-Haque for allegedly training with Lashkar-e-Toiba in Pakistan, a declared terrorist organisation under the Security Legislation Amendment (Terrorism) Act 2002.