Aged 96, Romantschenko met his death when a Russian bomb hit his apartment building in Kharkiv on March 18, according to broadcaster Radio Free Europe/Radio Liberty.
During World War II, Romantschenko survived the Buchenwald, Peenemünde, Dora and Bergen-Belsen concentration camps and later worked to keep alive the memory of Nazi German crimes, Poland's tysol.pl website reported.
It said Romantschenko was deputy chairman of the Buchenwald-Dora International Committee.
“We are stunned,” the Buchenwald and Mittelbau-Dora Memorials Foundation wrote on Twitter, announcing the man’s death, as cited by tysol.pl.
Monday was day 26 of the Russian invasion of Ukraine.
(pm/gs)
Source: tysol.pl, PAP, rferl.org, news.sky.com