STOCKHOLM -- A woman in her 70s is no longer suspected of having kept her son locked up in an apartment south of Stockholm for as long as 28 years, a Swedish prosecutor said Thursday.

Prosecutor Emma Olsson, who headed the preliminary investigation, told Swedish media that investigators found no evidence that the woman's son, who is in his 40s, had been kept in the apartment against his will.

The mother had been held on suspicion of unlawful deprivation of liberty and grievous bodily harm.

"We have not been able to find any evidence that any crime has been committed by the woman," Olsson told broadcaster SVT.

Swedish daily newspaper Expressen reported this week that the man was found Sunday by a relative who had learned that his mother had been admitted to a hospital. The relative went to the flat, found the door unlocked and entered.

The relative told the newspaper there was "urine, dirt and dust" all over the place and the apartment "smelled rotten." She heard a noise from the kitchen and found the man sitting on blankets and pillows.

According to the relative's account, he had no teeth, had sores on his legs and his speech was slurred. She alerted authorities afterwards.

Swedish news agency TT wrote that the relative was the man's sister and Olsson said the wounds came from illnesses, not from violence.

The investigation has not yet been formally closed, but the mother is no longer suspected of any crime and has been released.