The entire prison was placed on lockdown after the discovery on Tuesday. Everyone in the facility was ordered to stay in their wards, and daily operations were halted.
The police were called, and emergency services set up a tent where the shipment was opened.
But the powder turned out to be "some form of detergent," the police wrote on their website at 4 p.m. The case was closed and no criminal charges were filed.
Sagsjön is a women's prison and has security classes two and three. Class one is the strictest.
