Prisoners of war can be exchanged during a conflict – and some have occurred over the course of the war in Ukraine.

Government sources said Australia’s priority was Jenkins’ welfare and seeking to ensure his wellbeing and proper treatment in its representations to Russia. It was also reminding Russia of its obligations under international humanitarian law.

At least eight Australians have been killed since Russia launched its full-scale invasion of Ukraine in 2022. Dozens of Australians are believed to still be fighting, often paid as part of the foreign legion. Jenkins is the first known to be captured.

In video footage, Jenkins, speaking in both English and broken Ukrainian, gave his name and age and said he was a biology teacher who had joined the armed forces because he wanted to help Ukraine.

He underwent rapid-fire questioning from his captor about why he was in Kramatorsk, almost 700 kilometres east of Kyiv, and if he was being paid to fight.

“Where are you from?” his captor asked in the video, a version of which was circulated with English subtitles. A confused Jenkins was then slapped across the face when he did not understand.

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When asked his nationality, he replied: “I’m Australian.”

Jenkins is a former student at Melbourne Grammar, one of Victoria’s most prestigious schools. He graduated in 2010, studied biomedical sciences at Monash University and moved to China in 2015. Since 2017, he has been working as a lecturer at Tianjin College.

It is unclear when he left China and how long he has been fighting with Ukrainian forces on the frontline.

Those at Jenkins’ old Toorak Prahran Cricket Club were stunned on Monday when they learnt Russian soldiers had captured him.

One ex-schoolmate who did not wish to be named said Jenkins was “quirky, but a really great guy”.

“But after school, he lost contact with many of his friends,” they said. Jenkins moved away from “that sort of Melbourne Grammar upbringing”, the friend said, and focused on veganism and sustainability in China.

In one YouTube video last year, discussing his efforts to “force” people to turn vegan, Jenkins said he had lost touch with most people, apart from his mother.

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