article_snippet: An extraordinary collection of photographs and mementos chronicling the affair of a German businessman and his secretary in the late 1960s and 1970s has gone on show in New York.
article_snippet: The memorabilia was discovered in a briefcase three decades after the affair took place, abandoned in a German apartment and later sold at auction.
article_snippet: An extraordinary collection of photographs and mementos chronicling the affair of a German businessman called Günter and his secretary Margret (pictured) in the late 1960s and 1970s has gone on show in New York .
article_snippet: The memorabilia was discovered in a briefcase three decades after the affair took place, abandoned in a German apartment and later sold at auction .
highlights_snippet: Pictures and memorabilia found in an abandoned briefcase decades later .
  
highlights_snippet: Collection now on display in New York art gallery .