Benjamin Leefsma was a son of Louis Leefsma (deceased in 1932) and Rozette Elzas, who has survived the Holocaust. Benjamin was unmarried.
He had three other sisters: Esperance Nanette (Erna), Eliza Nanette and Regina Hanna. They too have been killed in the Shoah.
City Archive of Amsterdam, archive card of Benjamin Leefsma and Rozette Elzas.