Two of the three passengers in the helicopter were seriously injured, while a third person suffered minor injuries.
The accident occurred during a coordinated police excercise.
Fifteen fire fighters were sent to the scene but the helicopter is not reported to have caught fire.
The helicopter crashed at 10.30am near Sisjön, a lake to the south of Gothenburg.
“We don’t know how the accident happened,” said police spokesman Varg Gyllander.
Police have called in a crisis management group to tend to staff and the families of the victims.