The Swedish Academy's permanent secretary Peter Englund says the African country should free Dawit Isaak. He was imprisoned there eight years ago after demanding press freedom.

The academy awards the prestigious Nobel Prize in literature.

In an article published Thursday by dozens of Swedish newspapers, Englund says censorship "releases an acid that dissolves the very system it is perceived to protect."

Isaak fled to Sweden in 1987 as a war refugee but returned to Eritrea in the 1990s to become a reporter at an independent newspaper. He was among several journalists who were arrested and imprisoned without trial on Sept. 18, 2001.