"This is absolutely not something we want to be associated with," Kivik fair organizer Tony Andreasson told The Local on Wednesday.
The Swedish Resistance Movement (Svenska motståndsrörelsen - SMR) spent around three hours at the market, dealing out flyers and selling its newspaper "Nationellt Motstånd" (National Resistance).
"They must have registered under another name. That is the only explanation. We have had trouble with groups like this before," Andreasson said.
The group, which has been classified by the Swedish Security Service (Säpo) as "Sweden's greatest internal threat", boasts of the success of its recruitment drive on its homepage saying that "several debates" were held with fairgoers.
"The activists... made contact with one person who wanted to join the freedom fight," the group wrote.
Kivik fair is an annual event with a fairground and arund 1,000 market stalls selling produce from the region and elsewhere. The fair attracts more than 100,000 visitors per year.
Andreasson told The Local that two guards will be employed before next year's fair to ensure that the occasion is kept free from neo-Nazi groups.
"We are the people who decide over Kivik fair. We want to have a serious family market just as we have done for the past 25 years," he said.
The Local reported last week that SMR's newspaper had been reported for hate speech after it allowed a reader comment containing racial slurs to remain on the site.