Jeno Schwarcz was born in February 1928 in Munkacs, Czechoslovakia. On May 14, 1944, he was arrested, with his two sisters and parents, and deported to Auschwitz-Birkenau. When they arrived at the camp they were separated and Jeno never saw his family again. He survived and was liberated from Bergen-Belsen in April 1945, unaware of his family's fate. He eventually moved to Britain, settled in Leeds, and took the name Eugene Black.
Mr Black told the audience at the launch of the archive how the records had helped him, more than 70 years after being separated from his family.
"After continuous enquiries at Bad Arolsen I went to Germany in 2008 with my daughter to see the archives.
"Immediately I was made to feel at ease and my documents were produced: my identity card, my records, a list detailing my transportation, even a photo of me.
"I was shocked and surprised. They even had a certificate that would have allowed me to go to Palestine in 1945 after leaving Bergen-Belsen. I was not even aware the documents existed.
"I couldn't believe I was seeing them there, in black and white. I was taken up to an office and the lady said: 'Mr Black, I have news for you. Your two sisters did not perish in the camps but were selected for slave labour and were sent to an oil refinery in Gelsenkirchen.'
"My sisters were killed when the SS denied them access to a shelter during an RAF raid on the refinery.
"I broke down and cried. For 64 years I believed my sisters perished with my parents in the gas chambers.
"The very next day we went to the cemetery in Gelsenkirchen to pay our respects. I have been back three times since.
"I would never have known if it was not for the hard work put into creating these documents. I'm delighted that the archives will be available for people here in Britain who were not aware they existed."