A Chinese spy ship that has been closely tracked by the Australian Defence Force has now arrived off the coast of Queensland to monitor joint military exercises.

Key points: Defence sources say the Chinese spy ship is staying just outside Australia's territorial waters in the Coral Sea

Defence sources say the Chinese spy ship is staying just outside Australia's territorial waters in the Coral Sea International interest is expected in Exercise Talisman Sabre war games involving Australian, US and Japanese militaries

International interest is expected in Exercise Talisman Sabre war games involving Australian, US and Japanese militaries Spy ship is equipped with advanced communications systems for eavesdropping

Late last week the Chinese surveillance vessel began making its way south towards Australia ahead of the start of Exercise Talisman Sabre involving Australian, US and Japanese militaries.

Sources have told the ABC the spy ship has now reached Australia's "exclusive economic zone" in the Coral Sea, but is staying outside territorial waters.

The Defence Department says it is expecting international interest in Exercise Talisman Sabre, but has referred questions about movements of Chinese vessels to Beijing.

The Chinese ship had reached Australia's exclusive economic zone but was staying just outside territorial waters. ( Australian Government: Geoscience Australia )

The Auxiliary General Intelligence (AGI) is fitted with advanced communications systems designed to eavesdrop on other militaries, and is the same class of vessel that the ABC revealed had been monitoring the 2017 Talisman Sabre war games.

The ABC has been told the surveillance vessel is the Tianwangxing, which translates as "Uranus".

The Dongdiao-class vessel belongs to the People's Liberation Army's East Sea Fleet which is based in Zhejiang Province, and was commissioned in late 2010.

On board the Dongdiao AGI 853, are several clearly visible spherical domes, which shield dish antennas that collect and intercept radio signals and give it a distinct profile.

Defence experts say the extremely powerful antennas "hoover up" massive amounts of valuable data and intelligence where ever the ship travels.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 33 seconds 33 s High-tech Chinese spy ship makes its way towards Australia

Up to 25,000 military personnel, mainly from the United States and Australia, are taking part in this year's war games, which are focused on planning and conducting mid-intensity "high-end" warfighting.

Defence sources believe the Chinese are particularly interested in how its Maritime Self-Defence Force operates with the ADF and the United States.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 51 seconds 51 s A joint exercise between the US Navy and Australian military to take part in Queensland and the Northern Territory

"This year's Talisman Sabre involves the Japanese Amphibious Rapid Deployment Brigade, which was created last year primarily as a response option for potential Chinese incursion in the Senkaku Islands", a military official told the ABC, speaking on the condition of anonymity.

"Their capability and interoperability with Australia and the United States will be of interest to Beijing."

Lieutenant General Greg Bilton would not comment on exactly how the ADF would respond to the presence of the ship.

"I'm not going to go into operational details, but we'll just take appropriate actions in regards to that vessel," he said.

"It's a vessel that collects information, so it's not a great threat but we'll take appropriate action."

Just last month three Chinese warships caught locals by surprise after arriving in Sydney Harbour for a visit which was not publicly announced in advance by the Australian Government.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Watch Duration: 40 seconds 40 s Chinese warships made a surprise visit to Sydney Harbour in June

In May, the ABC revealed the Australian Navy had been closely followed by the Chinese military during a recent transit of the South China Sea, near islands controversially claimed by Beijing.

The Defence Force later confirmed that Australian Navy pilots had been targeted by laser attacks in the disputed waters, with Chinese maritime militia vessels believed to be responsible.