The country's top intelligence agency says it has been unable to investigate all "harmful espionage" and "foreign interference" against Australia due to the large scale of "malicious" activity directed here in the past year.

Key points: ASIO says foreign powers attempting to "advance their own country's own political objectives" through interference

ASIO says foreign powers attempting to "advance their own country's own political objectives" through interference The ASIO document stops short of identifying countries suspected of spying

The ASIO document stops short of identifying countries suspected of spying The assessment follows warnings about Chinese Government interference on university campuses

In its annual report, the Australian Security Intelligence Organisation (ASIO) says it has identified "a number of states and other actors conducting espionage and foreign interference against Australia".

"Foreign intelligence services sought access to privileged and/or classified information on Australia's alliances and partnerships, our position on international diplomatic, economic and military issues, our energy and mineral resources, and our innovations in science and technology," the report says.

Over the past 12 months ASIO says it identified "foreign powers clandestinely seeking to shape the opinions of members of the Australian public, media organisations and government officials" to try to "advance their country's own political objectives".

The domestic spy agency found "ethnic and religious communities" were also "the subject of covert influence operations designed to diminish their criticism of foreign governments".

ASIO Director Duncan Lewis calls espionage and foreign interference an "insidious threat". ( ABC News: Marco Catalano )

ASIO's assessment follows recent public warnings from Australian officials about the level of Chinese government interference on university campuses.

"Interference by foreign actors can undermine Australia's sovereignty by advancing a foreign state's cause through covertly interfering in Australia's political system and seeking to unduly influence public perceptions of issues," the report says.

The ASIO document stops short of identifying individual countries it suspects of spying, but Government officials believe China is becoming more aggressive with its activities against Australia.

"Foreign interference in Australia's diaspora communities through harassment or other means can erode the freedoms enjoyed by all people living in Australia," ASIO Director General Duncan Lewis writes.

"These activities — undertaken covertly to obscure the role of foreign governments — represent a threat to our sovereignty, the integrity of our national institutions and the exercise of our citizens' rights.

"While the harm from espionage and foreign interference is immediately evident in some cases, in other instances the harm may take years to eventuate.

"Espionage and foreign interference is an insidious threat — activities that may appear relatively harmless today can have significant future consequences."