A Swedish government study says there's been a recent surge in the number of automated Twitter accounts ahead of the September 9 election, noting that 40 per cent of them are more likely to support the anti-immigration Sweden Democrats party, expected to make gains.
The study by Sweden's defence research agency comes amid broader concerns over misinformation ahead of the election.
Researcher Johan Fernquist says the number of so-called Twitter bots discussing politics nearly doubled from July to August.
The report published on Wednesday said users "may be led to believe that this content (is) more widely accepted or more mainstream than it actually is." Swedish authorities repeatedly have talked about the potential risk of foreign inference in the vote.
Polls suggest the Sweden Democrats could become Sweden's second largest party.