Her lawyer came up with two very old witnesses who claimed that "in 1864 everyone in Gorcum knew that Kaatje was the illegitimate daughter of De Vries".

Nevertheless, Wery was arrested a year later because she was not wearing a star and sent to Amersfoort concentration camp.

Her husband, who was involved in foreign exchange smuggling and black trading in securities and diamonds, died in a car accident in late 1943.

In early 1944, Wery took up residence under the name Bella Tuerlings in an apartment at 26 Rubensstraat in Amsterdam.

She infiltrated her husband's network of black traders and handed several of them over to her colleague Dries Riphagen, a notorious Jew hunter.

She was regularly visited by SD chief Willy Lages at her hiding place, with whom she probably had a sexual relationship.

In October 1944 she moved to Brussels, which had meanwhile been taken by the Allies, and there she got into a relationship with Oreste Pinto, the local head of the Dutch counterintelligence service.

She obtained proof of political reliability, partly because thanks to her the double agent Christiaan Lindemans (also known by his alias King Kong) had been arrested.

Wery made headlines again when she introduced single women to Henk van der Meijden's TV-Privé television program at the end of 1979.

The film is based on the book of the same name by journalists Bart Middelburg and René ter Steege.