Bill Cosby has refused to answer a journalist's questions on allegations that he sexually assaulted several women over decades.
The 77-year-old comedian has seen scheduled appearances on the Late Show with David Letterman and The Queen Latifah Show cancelled and postponed amid the growing controversy.
The host of Weekend Edition Saturday on America's NPR radio station was speaking to Cosby and his wife, Camille, about their loan of more than 60 pieces of art to the Smithsonian's National Museum of African Art in Washington.
After a relaxed discussion, presenter Scott Simon changed the subject, saying it gave him "no pleasure" to question him on the allegations.
In the silence, Simon said "you're shaking your head" before urging him to take the chance to deny the alleged crimes, but Cosby did not say a word.
He has not been charged with any cases and settled a civil lawsuit in 2006 with a woman over an alleged incident two years before. The terms of the settlement were not disclosed.
