Bomb disposal experts were called to the north west of the city on Wednesday after a concerned janitor called the police.
While out sweeping rubbish from a parking lot, he had noticed a small parcel moving about in a most unusual manner.
Police arriving at the scene immediately sealed off the area and called in the bomb squad.
A recent spate of infighting among rival gangs has put police in the city on high alert. But on this occasion the infamous west coast biker gangs can probably be ruled out of the equation.
When, having excerised great care, the explosives experts finally got the package open they discovered nothing more dangerous than a throbbing vibrator.
Relieved police officers were able to remove the cordons before taking the battery-operated toy to the local station.
“But we don’t really expect anybody to come asking for it,” spokesman Jan Strannegård told Göteborgs-Posten.