Isaac Polak a son of Raphael Polak and Judic Isaac Lewijt. He married in Amstkerdam on 26 May 1926 to Catharina Lisser, daughter of Alexander Lisser and Vogeltje Cohen.
The couple had two children. The family lived at 8 Kerkstraat in Bussum. They were forced to move to Amsterdam. They went into hiding in Amsterdam at 191 Lijnbaansgracht. They were caught there on 21 March 1944 and a few items of jewellery and silver objects were seized at the time. Isaac Polak's wife and their children survived the sjoa however their daughter Margaretha died soon after her return, on 7 February 1946.
The archive of the Stichting Sieraden-Comité contains a large amount of correspondence, a statement of the right to inheritance from 1960 and a list of stolen items of jewellery.
NIOD, Records Stichting Sieraden-Comité, film 581, nr 820 file 70, website www.wiewaswie.nl and an addition of a visitor of the website.