Bob Dylan's failure to acknowledge his Nobel Prize in literature is "impolite and arrogant", according to a member of the body that awards it.
The 75-year-old singer was named the shock winner of the prize last week.
But all efforts by the Swedish Academy to contact him have failed, and he has not acknowledged the win in public.
Academy member Per Wast berg told Swedish television: "He is who he is," adding that there was little surprise Dylan had ignored the news.
"We were aware that he can be difficult and that he does not like appearances when he stands alone on the stage," he told Sweden's Dagens Nyheter newspaper in a separate interview.
A reference to the prize was removed from Dylan's website last week.
It is still not known if he will travel to Stockholm to receive the