The organization, which is in charge of administering sickness benefits and other forms of handout, investigated a randomly selected group of 10,000 benefits claimants. Five percent of these claimants are to be investigated further due to suspicions that their claims are fraudulent.
The figures do not include people cheating the state out of unemployment benefit, which is administered separately.
Curt Malmborg, head of the administration, says that perhaps one percent of all claimants could be told to pay back their benefits, to a total estimated value of a billion kronor.
Most of the suspected fraudulent claims concern sickness benefits, benefits paid to parents looking after sick children and housing benefit.