DNA testing determined a wolf, not a dog or dogs, was responsible for the attacks in October and November, The Local.se reported.
The sheep were killed as they grazed on an artillery range near Kivik in Skane, Sweden's southernmost county.
"The attacks looked like typical dog attacks, but in order to rule out the possibility of a wolf being behind them we ordered a DNA analysis," Nils Carlsson, a predatory animal inspector, said.
After one especially deadly night, the carcasses of 10 sheep were found in the morning on the range, which is also used for cattle and horses. They had been bitten and clawed.