BZ printed a picture of Christmann with Sammy Brauner, son of German movie producer Atze Brauner.
Kingsley, who played Mahatma Gandhi in Richard Attenborough's film, married Christmann in October 2003.
"I've split from Ben. Sammy is my new boyfriend now. We are a couple and we are really happy," the tabloid quoted Christmann as saying, while holding hands with Brauner at a party.
Kingsley, who was born Krishna Bhanji, has decided to file for divorce. This was his third marriage.
Photograph: Getty Images