After the war, his father refused to accept any awards from Denmark's post-war government, because many officials who had collaborated with the Germans, were still unpunished, in positions of power and were now posing as anti-Nazis.
Haaest was intimately familiar with the subjects of Danish resistance, and Danish pro-Nazi collaborators.
On 18 July 2007 the newspaper Information wrote that Haaest in September 1977 had published a pamphlet asserting that the nazi concentration camp gas chambers never existed and that the Diary of Anne Frank was a forgery.
This caused the Danish Arts Council to be condemned since it had funded Haaest's research into Danes who had served in the SS.
Information subsequently brought a retort from Haaest where he claimed to have been deliberately misquoted and referred to the allegations as an outrageous lie made to discredit and sabotage his authorship regarding Danish pro-nazi collaborators.