Initial tests suggest no-one else was involved in the death of a woman in Ipswich at the weekend.
The body of a woman, in her 40s, was found at a property on Meridian Rise at about 08:20 GMT on Saturday.
Further tests will be carried out after a post-mortem examination proved inconclusive, but inquiries are ongoing, Suffolk Police said.
A man, in his 40s, who was arrested on suspicion of murder has now been released under investigation.
His bail has been cancelled.
Suffolk Police said the woman’s death was being treated as “unexplained”.
Officers were called to the property following a call from the ambulance service.
Door-to-door inquiries were carried out in the area to the north of Woodbridge Road.