The woman, 51, was found dead in her apartment on Lilla Essingen on Sunday. The man, who was in the apartment at the time, was arrested on suspicion of serious assault, with the alternative charge of manslaughter.
“We do not currently have enough evidence for murder, but he is likely to have had some involvement in her death,” said Lars Marklund of Stockholm police.
The man has been questioned, but his responses have not been believable, according to Marklund.
The emergency services were alerted on Sunday afternoon to an incident in an apartment on Lilla Essingen. The caller said that an ambulance was needed. Police also came to the scene. The dead woman was found in the apartment.
Police forensic experts searched the apartment during the afternoon and evening, while the woman’s body was examined by pathologists. A cause of death had not been ascertained by early Monday morning.
The man being held by police was in a relationship with the woman. Police say he did not call the emergency services; the call was made by a neighbour.