Here's some stuff on HAMSUN from WIKIPEDIA, a lousy source but hell, it's so readily available.
"...Hamsun was a prominent advocate of Germany and German culture, as well as a rhetorical opponent of British imperialism and the Soviet Union, and he supported Germany both during First and the Second World War. Despite his immense popularity in Norway and around the world, Hamsun's reputation for a time waned considerably because of his support of Vidkun Quisling's National Socialist government. Following a meeting with Joseph Goebbels in 1943, he sent Goebbels his Nobel Prize medal as a gift.
While in his 80s, and largely deaf, Hamsun met with Adolf Hitler. His audience with him is recorded to have been mostly him complaining about the Nazi depredations against Norwegians. Hamsun tried to have him remove Josef Terboven from the position of Reichskommissar of Norway.
According to Bennett Cerf's book Try and Stop Me, after Hamsun's alliance with the Quislingites became widely known, angry Norwegians sent copies of his books back to his hometown in such numbers that the small post office in the town had to hire temporary workers to assist in handling the volumes of books arriving.
After Hitler's death, Hamsun wrote an obituary in the leading Norwegian newspaper Aftenposten, describing him as a "warrior for mankind". It has been argued that his "sympathies" were those of a country that had been occupied. He sometimes used his status as a man of fame to improve the conditions of his area during the occupation and criticized the number of executions. Still, following the end of the war, angry crowds burned his books in public in major Norwegian cities. After the war Hamsun was confined for several months in a psychiatric hospital. A psychiatrist concluded he had "permanently impaired mental abilities", and on that basis the charges of treason were dropped. Instead, a civil liability case was raised against him and in 1948 he was fined 325,000 kroner for his alleged membership in Nasjonal Samling, but cleared of any direct Nazi-affiliation. Whether he was a member of Nasjonal Samling or not and whether his mental abilities were impaired is a much debated issue even today. Hamsun stated he was never a member of any political party. Hamsun himself wrote about this experience in the 1949 book, On Overgrown Paths, a book many take as evidence of his functioning mental capabilities.
The Swedish author Thorkild Hansen investigated the trial and wrote the book The Hamsun Trial (1978), which created a storm in Norway. Among other things Hansen stated: "If you want to meet idiots, go to Norway", since he felt that treating an old man like that was outrageous...".
Here's something from the people who administer the NOBEL prizes:
"...Hamsun's admiration for Germany, which was of long standing, made him sympathetic toward the Nazi invasion of Norway in 1940..."
If any of this stuff above is even remotely accurate, and HAMSUN was indeed a supporter of the Hitlerites, then he's a scum-bag. A collaborator. A traitor to his own people. Of course, I'm liberal enough to not advocate the banning of his books because if you do that, then the Hitlers and the Hamsuns win.