The Nobel Foundation has rejected calls to revoke the Nobel prize awarded to German writer Guenter Grass, following revelations about his wartime past.
Grass said he felt ashamed of his service in the Waffen SS
Grass admitted in a newspaper interview on Saturday that he had served in Hitler's elite force, the Waffen SS.
This prompted attacks by writers, historians and politicians. Some called for him to be stripped of his Nobel prize for literature, awarded in 1999.
But the head of the Nobel Foundation said prize decisions were irreversible.
On Tuesday Grass said his literary achievements were being denigrated following his belated admission.
'Life of shame'
"What I'm experiencing is an attempt to make me persona non grata, to cast doubt about everything I did in my life after that - and that later life was marked by shame," he told Germany's ARD television.
He was speaking ahead of the publication of his war memoirs next month.
"Everything I have to say about the matter is in it," Grass told ARD.
Meanwhile the mayor of the Polish city of Gdansk (formerly Danzig) - where Grass was born - rejected suggestions that the author should be stripped of his honorary citizenship of the city.
The mayor, Pawel Adamowicz, said he opposed submitting the affair to the municipal council saying it was not for the council to judge history.
Grass became world-famous after his first novel The Tin Drum was published in 1959.
Should Guenter Grass be stripped of his Nobel prize for literature? At what point should you draw a line under history?
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