The 49-year-old designer was found hanging from a balcony door handle by her assistant, Brittany Penebre around 10 am on Monday. Penebre called 911 and Scott was pronounced dead at the scene, reported the New York Post.
A spokesperson for Jagger said the rocker, who was in Australia for a Rolling Stones tour, is completely shocked and devastated by the news and is racing back to New York.
The couple had been dating since 2001
The New York Police Department spokesman did not confirm the identity of the dead person but said she was 49 years old and had been found unconscious and unresponsive. The police will not identify her until the family is notified. Authorities reportedly believe the death was a suicide, but the cause is yet to be determined.
Scott's death comes following the cancellation of her London show which she had blamed to production delays. The designer was planning to unveil her fall 2014 collection via social media earlier this month but that too had been delayed.
Scott was a well-known name in the fashion circles and had designed for A-list stars like Nicole Kidman, Julianne Moore, Sarah Jessica Parker. She also coordinated Jagger's wardrobe for The Rolling Stones' tour in 2012.
New York Post cited sources saying that Scott had recently split from Jagger and was in debt to the tune of USD 5.9 million.
The 6-foot-3 Scott used a black scarf to hang herself from a balcony door handle. There was no note, no evidence of drugs and no sign of foul play, the sources said.
However, the rocker's representative denied that they had split.
Scott had apparently texted a message to Penebre around 8:30 am to come by her apartment only to be found dead.