An Australian helicopter was flying south-east of China’s Shandong peninsula but outside its territorial waters when a Chinese fighter aircraft released flares in its path, new documents show.
Guardian Australia can reveal that Australia’s HMAS Hobart warship was also being shadowed by a People’s Liberation Army (PLA) navy destroyer and another Chinese helicopter at the time of the 4 May standoff.
The incident emerged as another flashpoint in tensions between the two countries, casting a shadow over attempts to “stabilise” the diplomatic relationship.
The Australian government still refuses to reveal the exact location of what it considers to be an “unsafe and unprofessional” release of flares, but documents obtained under freedom of information (FoI) laws reveal more details than previously disclosed.
The documents include briefings the defence minister, Richard Marles, received from his department about the incident in the Yellow Sea, which covers an area between the Chinese mainland and the Korean peninsula.
One email sent on the evening of Sunday 5 May noted that HMAS Hobart “was operating in the Yellow Sea, south-east of the Shandong Peninsula, undertaking Operation Argos”.
This is the name the Australian defence force (ADF) gives to its operation that aims to monitor and deter ship-to-ship goods transfers in breach of UN sanctions on North Korea.
“HMAS Hobart’s embarked MH-60R helicopter was airborne during this period,” the email from the director of military strategic commitments said.
“HMAS Hobart was being shadowed by a PLA-Navy (PLA-N) destroyer (DDG-113) and the embarked … helicopter from that vessel.”
The email said when flares were released “within approximately 300 metres” of the MH-60R Seahawk helicopter, it had to manoeuvre to avoid the flares.
“On this basis the intercept was assessed as UNSAFE.”
The email said a formal protest would be made to the PLA’s defence attache in Canberra the following day, and the Australian embassy in Beijing would make similar arrangements “as soon as practicable”.
The email said defence’s international policy division “will work with you” and also the prime minister’s department and the foreign affairs department “to determine the approach to publicising this incident”. The recipients of this email were blanked out.
The following evening, Nine News broke the story in a TV report that included quotes from an interview with Marles. Shortly after that report was aired, Marles and his department issued public statements more broadly.
The newly released FoI documents include a section marked “background – not for public release”.
It said the Australian helicopter “during its second mission” was shadowed by a PLA air force jet aircraft and had to take “urgent avoiding action” when flares were released at close range.
A ministerial background brief elaborated: “The MH-60R then communicated to the PLA aircraft that it was departing the area due to safety concerns and returned to HMAS Hobart where it landed safely.”
The exact location of the incident was blanked out in the documents released to Guardian Australia.
But independent observers said the documents appeared to confirm the incident occurred beyond the Chinese territorial sea (extending out to 12 nautical miles) and the Chinese contiguous zone (extending out to 24 nautical miles).
They said this meant that, at a minimum, the incident must have occurred 24 nautical miles off the Chinese coast, likely within China’s exclusive economic zone (EEZ).
The US and Australia are among countries to argue such activities are allowed within such zones and insist on exercising “freedom of navigation” there.
An international law expert at the Australian National University, Prof Don Rothwell, said China contested the right of foreign navies to conduct military operations in its EEZ.
“Australia’s refusal to precisely identify where the Yellow Sea interactions with the PLA took place between HMAS Hobart and its embarked helicopter is unhelpful,” Rothwell said.
“The term ‘international waters’ is not used in the United Nations Convention on the Law of the Sea, and in the Yellow Sea could possibly extend to maritime zones legitimately claimed by China or South Korea.”
Rothwell said Chinese-flagged vessels had “a record of operating in the Yellow Sea in violation of the UN’s North Korea sanctions”.
One of the new documents said Australia had, since 2018, “periodically deployed maritime surveillance aircraft and naval vessels to work alongside Five-Eyes and other partners (such as Japan, Republic of Korea, and France) to monitor and deter illicit ship-to-ship transfers of sanctioned goods”.
It said the helicopter was conducting an Operation Argos “maritime domain awareness mission when it was intercepted”. It said the use of the helicopter for such a mission was “a normal mode of operation”.
When contacted for comment on the new documents, the Australian government said specific locations “cannot be provided for operational security reasons”.
A defence spokesperson said it was “a routine occurrence for ADF assets operating in the region to have interactions with the PLA”, and most of those interactions were “safe and professional”.
The spokesperson added that sovereign states were “free to conduct shadowing in international waters, provided that activity constitutes a safe interaction”.
“All missions by ADF assets are conducted in international waters and airspace, in accordance with international law.”
After the incident was publicised, a Chinese foreign ministry spokesperson accused Australia of “provocative” behaviour by flying “within close range of China’s airspace”.
The prime minister, Anthony Albanese, said this language proved ADF personnel were “in international waters and airspace”.
China’s ministry of national defence later argued Australia was trying to “conduct close-in reconnaissance and disturb the normal training activities” of a Chinese naval fleet conducting exercises in the Yellow Sea.
The ministry said the PLA had “conducted legitimate, reasonable, professional, and safe operations to expel it”.
The Chinese premier, Li Qiang, visited Australia in June. Albanese said the leaders had discussed improving military-to-military communications “so as to avoid incidents”.
