Fashion designer and girlfriend of Rolling Stone Mick Jagger, L'Wren Scott has been discovered dead in an apparent suicide in her Manhattan apartment.

Authorities have reported that the former model was discovered by her assistant today, in a suspected suicide.

An NYPD press officer told the HuffPost UK that the department responded to a call at 10.05am to an 11th Avenue address where they found a 49-year-old woman unconscious and unresponsive and was later declared dead.

The press officer informed the site that a medical examiner will determine the cause of death pending family notification.

A spokesman for Mick Jagger said the singer was "completely shocked and devastated" following the news of her death.

The 6'4'' designer was known for her eponymous label, which she launched in 2006 following a successful career as a stylist and model.

Raised in Utah by her Mormon adoptive parents, Scott became a model as a teenager and at 18 she headed off Paris to walk for the likes of Chanel and Thierry Mugler.

It was later, after she moved to California in the 1990s, where she established herself as a stylist, working with celebrity photographer Herb Ritts. It was from here she built up her celebrity clients, such as Sharon Stone and Nicole Kidman, who she began advising exclusively.

From here her star rose even further and became one of the leading celebrity stylists in the world, working with Hollywood actresses, such as Julia Roberts for the cover W magazine in 2011.

She also gained acclaim for her work on films such as Ocean's Thirteen and Eyes Wide Shut, for which she designed the costumes. She also worked on the Martin Scorsesse documentary about the Rolling Stones, Shine a Light.

She has been in a relationship with Rolling Stones lead singer Mick Jagger since 2001.

Click here to see L'Wren Scott's career in photos

(Images: Rex Features)

L'Wren Scott found dead in her Manhattan apartment