The twins, born by Caesarean section, came into the world on July 11. But details were kept from the public until the press were invited to the clinic to see the delighted parents - Florence, 35, and the father Stephan, 40, and photograph them with their twin boys.
Hospital authorities said the non-identical, or biovular, twins were definitely full brothers, with the same father. The probability of a birth of this kind was one in a million.
"Ryan came first, and everything was as usual. But when Leo was born, I couldn't believe my eyes," Birgit Weber, the doctor who carried out the Caesarean said.
Weber said she had been present at 10 000 births over almost 20 years of hospital experience and had never seen anything quite like this.
Ryan, who weighed 2 650 kilograms, is distinctly lighter in skin colour than Leo, who was born weighing 2 606 kilograms.
Doctors at the clinic in the east of Berlin said a similar case had been recorded in Middlesborough in England last year. There is also reported to be a case in the eastern German city of Leipzig.
Florence, who has an 18-year-old son from a previous relationship, expressed delight with her boys.
"Ryan is the noisy one, and Leo quiet," she said.
The sight of her very different sons had initially left her speechless, she said.
The parents met each other at a party 10 years ago, when Florence was living in the Netherlands. She subsequently moved to Potsdam near Berlin, where Stephan works as a rock musician. - Sapa-dpa