Jozef de Leeuw was a son of Marcus Salomon de Leeuw and Ester Polak. He was married. The couple had two children. The family lived at 60 Bitterstraat in Zwolle. Jozef de Leeuw was a wholesaler.
D. Stibbe and J. Hagedoorn, Herinneringsboek joods Zwolle 1940-1945 (Zwolle 1995) 44-45
In addition, a Jokos file (number 5259) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.