The theft was recently discovered in the section for emergency pediatric care at the University Hospital in Uppsala.
It was staff who reacted to the fact that the drug did not work against pain as it should.
According to information to Expressen, someone must have emptied the morphine bags, intended for injection, and replaced them with another type of liquid.
In an email to Expressen, Klas Ekström, operations manager and chief physician at the children's hospital, writes that the incident was reported to the police.
"The case is handled by the Academic Hospital's security department, is reported to the police and is covered by preliminary investigation secrecy."