An Australian soldier and her husband have been arrested and each charged with spying for Russia.
Investigators say the couple - both Russian-born Australian citizens - obtained Australian Defence Force (ADF) material to share with Moscow.
However, Australian police say "no significant compromise" of military secrets has been identified.
It is the first time stricter foreign interference laws - introduced by Australia in 2018 - have been used to lay espionage charges.
Kira Korolev, a 40-year-old army private, and her 62-year-old husband Igor Korolev will face court in Brisbane on Friday, each on one count of preparing for an espionage offence – which carries a maximum 15-year jail sentence.
Australian Prime Minister Anthony Albanese said he had been "briefed extensively" by the nation's security agencies but would not comment on the case directly as it is now before the courts.