Chris Cornell's wife has disputed "inferences" that the rock musician killed himself in a hotel room, saying he might have taken more of an anti-anxiety drug than he was prescribed.
Wayne County Medical Examiner's Office said Cornell - the lead singer in Soundgarden and Audioslave - hanged himself after performing at a concert in Detroit, but his family said that without toxicology test results they do not know what caused his death.
His wife Vicky said that when she spoke to her husband after the show, he told her he may have taken "an extra Ativan or two".
According to lawyer Kirk Pasich, the 52-year-old musician had a prescription for the anti-anxiety drug. Ativan, a sedative, has side effects that can include drowsiness and dizziness, according to the National Institutes of Health.
"Without the results of toxicology tests, we do not know what was going on with Chris - or if any substances contributed to his demise," Mr Pasich said in a statement.
"Chris, a recovering addict, had a prescription for Ativan and may have taken more Ativan than recommended dosages.
"The family believes that if Chris took his life, he did not know what he was doing, and that drugs or other substances may have affected his actions."
Cornell had battled addiction problems in the past. He told Rolling Stone in a 1994 interview that he started using drugs at 13, and was kicked out of school at 15.
"I went from being a daily drug user at 13 to having bad drug experiences and quitting drugs by the time I was 14, and then not having any friends until the time I was 16," he said.
"There was about two years where I was more or less agoraphobic and didn't deal with anybody, didn't talk to anybody, didn't have any friends at all.
"All the friends that I had were still (messed) up with drugs and were people that I didn't really have anything in common with."
Mrs Cornell said her husband slurred his words when she spoke with him after the Detroit show. She said "he was different", and she contacted security to check on him.
"What happened is inexplicable, and I am hopeful that further medical reports will provide additional details," she said. "I know that he loved our children and he would not hurt them by intentionally taking his own life."
The medical examiner's office said on Thursday that it had completed the preliminary post-mortem on Cornell, but "a full autopsy report has not yet been completed".
Cornell was a leader of the grunge movement with Seattle-based Soundgarden - with whom he gained critical and commercial acclaim. He also found success outside the band with other projects, including Audioslave, Temple of the Dog, and solo albums.
Soundgarden's current tour kicked off in late April and was planned to run until May 27.
Grief-stricken fans left flowers at memorials across Seattle on Thursday for the musician whose forceful, sombre songs helped cement the city's place in rock history.
The city's Space Needle went dark at 9pm for an hour in tribute.
Cornell was born and raised in the city and was part of a close-knit group of artists who formed the foundation of what would become the grunge scene that exploded in the early 1990s, by combining the bombast of early 1970s heavy metal with the aggression and attitude of punk rock.