The BBC reported on Thursday that an inquest at Westminster Coroner's Court has found that O'Riordan died by drowning due to alcohol intoxication. Expert witnesses also said she had no injuries or evidence of self harm after she was found submerged in the bath in her room, and had "drunk an excessive amount of alcohol."
The BBC reports that toxicology tests showed she was more than four times over the legal limit for driving.
The court also heard that she had bipolar disorder but was getting treatment. However, she went through periods of excessive drinking.
In January, London's Metropolitan Police told ET that O'Riordan's death was not being treated as suspicious. A spokesperson for the police said Westminster officers responded at the time to a hotel where a "46-year-old woman was pronounced dead at the scene."
O'Riordan was in London at the time of her death "for a short recording session," her rep told ET in a statement.
“Family members are devastated to hear the breaking news and have requested privacy at this very difficult time," the statement added.
O'Riordan, who enjoyed success with The Cranberries with '90s hits like "Zombie" and "Dreams," performed for the last time in December. A number of singers paid tribute to the Irish singer after her death, including Bono and Johnny Depp.
For more on the late singer, watch the video below: