Czech-born author Milan Kundera, who wrote The Unbearable Lightness of Being, has demanded that a Czech weekly apologise for publishing allegations that he once informed on a purported Western spy, his representative said on Wednesday.

The Respekt weekly was given two weeks to apologise in a letter delivered to the publisher October 16, said Jiri Srstka, the director of the Dilia agency, which represents Kundera in the Czech Republic.

“We haven’t heard from them yet,” Srstka said. He said if Respekt does not comply, Kundera will sue.

Editor-in-chief Martin Simecka was quoted by the CTK news agency as saying the request is being studied by lawyers and Respekt will comment later.

On October 13, Respekt published an article written by a historian from the Institute for the Study of Totalitarian Regimes and co-signed by a Respekt journalist. The article reporting that a team of historians and researchers had found a Czech Communist police document identifying Kundera as the person who in 1950 informed on a man later imprisoned for 14 years.

The usually reclusive Kundera was quickly denied the charge, accusing the institute and the media of “the assassination of an author”.