Fashion designer L'Wren Scott, found dead in her high-rise Manhattan apartment on Monday, committed suicide by hanging, the New York City medical examiner's office said on Wednesday.
Police had been treating the death of the 49-year-old former model and stylist who was the girlfriend of Rolling Stones lead singer Mick Jagger as an apparent suicide after finding the her body with a scarf around her neck.
The Medical Examiner did not release any more details about her death. Her family has yet to announce funeral arrangements.
In a posting on his official website, Jagger, who had dated Scott since 2001 and was in Australia when he received news of her death, spoke of his distress and sorrow.
"I am still struggling to understand how my lover and best friend could end her life in this tragic way," he said in the post on mickjagger.com. "She had great presence and her talent was much admired, not least by me."
Jagger attended many of her fashion shows and the raven-haired 6-foot-three Scott was often pictured towering over her rock-star boyfriend at celebrity events.
The Rolling Stones postponed concerts in Australia and New Zealand after learning of her death. The group had been due to start the seven-concert leg of their world tour on Wednesday in Perth, Australia. Fans were told to keep their tickets until further information was released.
Scott's sleek, sexy designs were popular among Hollywood stars such as First Lady Michelle Obama and Nicole Kidman, who was also Scott's friend.
Although her gowns were featured regularly on red carpets, her company faced mounting debts. Last October in accounts filed in London her firm, LS Fashion Ltd, reported a loss of 4.3 million euros (US$5.99 million) in 2012, an increase from 3.0 million euros the previous year.
American fashion critic Cathy Horyn, who had known Scott since the mid-1990s when she worked as a stylist for photographer Herb Ritts, said Scott was planning to close her business and was going to make an announcement this week.
"Still, as painful as the decision must have been for her, I wouldn't draw any conclusions from it about her state of mind. Nor should any credence be given to reports of a breakup with Mick. It's rubbish," she wrote in The New York Times, where she was fashion critic from 1999 to earlier this year.