Russia's Ministry of Foreign Affairs said on Wednesday that Australia had contacted Moscow about the possible capture by the Russian army of an Australian citizen fighting with Ukrainian forces and that it was looking into the matter.
Maria Zakharova, a spokeswoman for the ministry, made the comments at a weekly news briefing in Moscow.
This week, a hostage video emerged of captured soldier and Australian man Oscar Jenkins being detained and interrogated by Russian forces in eastern Ukraine.
Pro-Kremlin social media accounts posted a video on Sunday showing a man with his hands tied and dirt across his face being hit across the head as an unseen person questions him in Russian.
In response, the man identifies himself as 32-year-old Oscar Jenkins and, speaking in both English and Ukrainian, says he is a biology teacher who lives in Australia and Ukraine.
He was asked about why he was in Kramatorsk — almost 700 kilometres east of Kyiv — and if he was being paid to fight.
The ABC has independently verified Mr Jenkins' identity.
Ms Zakharova's remarks appear to be Russia's first public comments on the matter after its ambassador to Australia Alexey Pavlovsky was called into a meeting at DFAT headquarters in Canberra on Monday but declined to comment as he entered and exited the building.
Diplomats are still working to confirm Mr Jenkins's condition and location and are urging Russia to treat him humanely.
Acting Foreign Minister Mark Dreyfus said on Monday that the federal government had made representations to Russia and urged them to comply with international law, while they worked to locate Mr Jenkins and provided consular assistance to his family.
Prime Minister Anthony Albanese also said on Monday that the video featuring Mr Jenkins was "concerning".
"We are working through the Department of Foreign Affairs and Trade to provide support including for this gentleman, trying to ascertain the details and the facts," he said.
"We know that the Russians often put out information that isn't right, so our embassy in Moscow is working but in addition to that Foreign Affairs and Trade are working here as well."
At least seven Australians are believed to have died fighting in Ukraine since Russia's invasion began in 2022, but Mr Jenkins is believed to be the first to be captured and held as a prisoner of war.
Reuters/ABC