On 23 June 1943 several members of the Prosper network were arrested by the Gestapo, including network leader Francis Suttill and Borrel, most likely due to an informer or traitor.
On 6 July 1944, 24-year-old Andrée Borrel and her three compatriots were given lethal injections of phenol, then incinerated in the camp's crematorium.