Russia has revealed that Australian prisoner of war Oscar Jenkins is alive, following grave fears that the former teacher had been executed.

Russia’s ambassador to Australia told officials Jenkins was detained by Russian Armed Forces while fighting for Ukraine, but was alive.

Foreign Minister Penny Wong said Australia had received the update, but serious concerns remained for his welfare.

“The Australian government has received confirmation from Russia that Oscar Jenkins is alive and in custody,” she said on Wednesday.

“We have made clear to Russia in Canberra and in Moscow that Mr Jenkins is a prisoner of war and Russia is obligated to treat him in accordance with international humanitarian law, including humane treatment.

“If Russia does not provide Mr Jenkins the protections he is entitled to under international humanitarian law, our response will be unequivocal.”

The Albanese government has called on Russia to treat the prisoner of war justly and release him.

Russian ambassador Aleksey Pavlovsky advised officials Jenkins was in custody on Russian territory and his health condition was “normal”.

Wong said she had also spoken with her Ukrainian counterpart and the International Committee of the Red Cross president.

Australia is working with Ukraine and the Red Cross to access Jenkins and independently verify his welfare.

Ukrainian ambassador to Australia Vasyl Myroshnychenko said it was good news Jenkins was alive.

But Russia’s refusal to confirm his status for more than a month put his family, friends and Australians through anguish and was “typical of that barbarous regime”, he said.

“We should strongly note that Russia is documented as killing and maltreating prisoners of war, as well as constantly lying on an industrial scale. It is a murderous misinformation machine that cannot be taken at its word alone.

“In line with international norms, Russia must therefore provide definitive video proof of Oscar being alive and, then more importantly, it should release him rather than use him as a human bargaining chip for its authoritarian aims.”

The Department of Foreign Affairs is providing consular assistance to Jenkins’ family.

He is the first Australian combatant reportedly captured by Russian forces and his death would have marked the first for an Australian prisoner of war in more than 70 years.

Prime Minister Anthony Albanese said Russian authorities had told Australian officials Jenkins was alive but he was reticent to offer official confirmation just prior to Wong’s statement.

“If that is the case, it certainly would be welcome,” he told ABC TV on Wednesday.

“It’s something that we have demanded information on and we are demanding more information so that we can be certain that what has been suggested is, in fact, the case.”

In a social media video circulated in December, Jenkins was shown speaking a mix of broken Russian and English.

The Russian embassy in Canberra has been contacted for comment.

-with AAP