Scott has been found dead after hanging herself in her Manhattan apartment on Monday morning. A spokesman for Mick Jagger said the singer, who is in Australia as part of the Rolling Stones tour, was ‘completely shocked and devastated’ following the news of her death. When asked if there were still in a relationship at the time of her death, he replied ‘of course’. The designer, 49, was found by her assistant and there was no immediate suspicion of foul play though the Medical Examiner has not yet released the formal report.

A spokeswoman for New York City Police Department said: ‘A 49-year-old female was found this morning at 10.05am at 200 11th Avenue. She was unconscious. She was pronounced dead on arrival by the emergency medical services. The investigation is ongoing. We are awaiting medical examiners to determine the cause of death.’

There was little to cause suspicion ahead of the shattering discovery, as her official Twitter account was updated at 11am — an hour after her body was reportedly found. She was found hanged to death in her apartment on the eighth floor of a luxury building in Chelsea where Nicole Kidman — one of her most famous fans- also has a flat.

The Mormon-raised designer has been romantically linked to the Rolling Stones frontman since 2001. The couple met on the set of a photo shoot in 2001 when she was working as the stylist on call. They made for an unlikely pairing: as well as being 23 years Mick’s junior, at 6ft 3in, she stands head and shoulders above her 5ft 8in lover.

Scott split her time between London, where she has a design studio in Chelsea, and New York. She and Jagger also own an apartment on Paris’s Left Bank that once featured in Vogue.

She ranked among The Hollywood Reporter’s 25 Most Powerful Stylists in 2011, 2012 and 2013, but failed to make the list this year. Fans including Oprah Winfrey, Sarah Jessica Parker and Michelle Obama. She had even been tipped to design Angelina Jolie’s wedding dress.

Scott first broke into the fashion industry as a model and then a stylist before launching an eponymous line in 2006 that was a major hit with celebrities.

She continued to widen her brand and at the end of last year, she launched a collaboration with Banana Republic, starring alongside models in the ads.

Her name was originally Luann Bambrough until she changed it to the more exotic ‘L’Wren’ when she launched her modelling career at age 17. She stood at 6ft 3in tall and caught the eye of celebrity photographer Bruce Weber who advised that she move to Paris to pursue a career as a model where she went on to work for Thierry Mugler and Chanel.

Then in the 1990s she moved to California and established herself as a stylist which led her to work closely with photographer Herb Ritts and Karl Lagerfeld. She has styled many celebrities including Madonna, Julia Roberts and Tom Hanks.

She launched her first designer collection, named ‘Little Black Dress’, in 2006. It achieved huge success — particularly her figure-hugging ‘Headmistress’ dress — with celebrity fans including Sarah Jessica Parker and Michelle Obama.

L’Wren also worked styling costumes on film sets including Ocean’s Thirteen, Eyes Wide Shut and Shine a Light, a Martin Scorsese documentary about the Rolling Stones.

The designer had been especially busy of late too. At the end of last year, she designed a holiday collection for Banana Republic — but last month she shocked the fashion set when she cancelled her London Fashion Week show at short notice. The designer blamed production delays in key show and couture pieces, according to WWD.