The district court pressed that Aron Flam should be released because the cover of his book "This is a Swedish tiger" is satire.
On the cover, Bertil Almqvist's emergency ladder can be seen intact and one arm has been fitted with a swastika.
According to Flam, the book is a settlement with the Swedish culture of silence during the Second World War.
"After analysis of the Patent and Market Court's ruling, I have made an overall assessment and come to the conclusion that the case needs to be tried in a higher court," says chamber prosecutor David Ludvigsson in a press release.