Chris Cornell’s family is disputing the findings of the Wayne County Medical Examiner’s Office, which ruled that the Soundgarden frontman died from suicide by hanging.

Lawyers for the family issued a statement Friday morning that read, “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.”

According to the family, toxicology tests are necessary to give some insight into what may have spurred his actions.

Cornell was in Detroit for a Soundgarden show when he died. He performed a concert Wednesday night then returned to his hotel room, where he was found unresponsive hours later.

According to the statement, the family believes the prescription anti-anxiety drug Ativan may have had some role in Cornell’s death.

“Some medical literature indicates that Ativan can cause paranoid or suicidal thoughts, slurred speech and impaired judgment,” the statement read.

Cornell’s widow, Vicky, echoed this theory in her own statement, saying that the singer had acted normally earlier in the week but seemed different when she spoke to him Wednesday.

“When we spoke after the show, I noticed he was slurring his words,” her statement read. “When he told me he may have taken an extra Ativan or two, I contacted security and asked that they check on him. What happened is inexplicable and I am hopeful that further medical reports will provide additional details. I know that he loved our children and he would not hurt them by intentionally taking his own life.”