Lemekhani Nathan Nyirenda, 23, who had been serving a prison sentence in Moscow, "passed away on 22nd September 2022, in Ukraine," Zambian minister Stanley Kakubo said in a statement, adding he died "at the battlefront."
"The Zambian government has requested the Russian authorities to urgently provide information on the circumstances under which a Zambian citizen, serving a prison sentence in Moscow, could have been recruited to fight in Ukraine and subsequently lose his life," Kakubo added
The statement said Nyirenda, who had been studying nuclear engineering at the Moscow Engineering Physics Institute, had been handed a jail term in April 2020 of nine years and six months.
He was incarcerated at Tyer medium security prison on the outskirts of the city, it said. The statement did not specify the alleged offense.
Niyrenda's remains have been transported to the Russian border town of Rostov ahead of repatriation to Zambia, the statement added.
Several Ukrainian soldiers on the front line in Bakhmut told AFP last month that alleged convicts and ex-convicts were being used as bait to draw fire and reveal Ukrainian positions.
Ukrainian officials say the Wagner mercenary group has been sending thousands of soldiers recruited in Russian prisons to the front line, with the promise of a salary and an amnesty.
According to Ukrainian President Volodymyr Zelensky, Wagner may have recruited up to 2,000 former prisoners to fight.