The 70-year-old is no longer suspected of committing any crime after her arrest on suspicion of grave bodily harm and unlawful deprivation of liberty.
She was initially accused of having held her 41-year-old son in her apartment in Stockholm for the past 28 years.
The mother was reported to the police after a family member broke into the apartment and found the man pierced in the cuts and pus, had lost all his teeth, and was unable to speak. Her relative also described the apartment as being covered with “urine, dirt and dust,” she told the Swedish newspaper Expressen.
The Stockholm public prosecutor told Reuters the man had been taken to a hospital for surgery.
The preliminary investigation eventually found no evidence to suggest that the man was being held in the apartment against his will.
“We could not find any evidence that the woman had committed any crime,” prosecutor Emma Olson told SVT.
Olson also said the man’s injuries were most likely the result of the disease, according to Swedish news agency TT.
While the man’s mother is no longer facing charges, the official investigation has not been closed.
“One can question her suitability as a mother, but it is now up to social services to consider it,” Olson told AFP.