Two residents at a nursing home in Arvidsjaur had their morphine tablets replaced with differently colored and glittery tablets, which SVT News Norrbotten was the first to report on.
The unknown pills were allegedly repainted to resemble real morphine tablets, but the forgery was discovered when a nurse went through one of the residents' medication.
After the initial discovery, all residents' dosages were reviewed, and it was found that another person had been affected.
The medications were stored in locked cabinets, according to P4 Norrbotten.
The incident has been reported to the Health and Social Care Inspectorate (Ivo) under the Lex Maria regulations.