The heiress to the Johnson & Johnson fortune has been found dead at her Los Angeles home.

Casey Johnson, 30, had a history of drug abuse. Police said she appeared to have died from natural causes, although a cause of death has not been determined.

She was reportedly engaged to actress and model Tila Nguyen, better known as Tila Tequila.

According to gossip website TMZ, Johnson’s body was believed to have lain in the house for several days before being discovered yesterday morning.

A number of celebrity friends used Twitter to express their sadness.

Lindsay Lohan wrote: “r.i.p. To a friend to and of many – Casey Johnson – my regards to her family, friends and her beautiful daughter Ava you are in our hearts CJ”.

However, Lohan’s ex-girlfriend Samantha Ronson added: “Am so sick of those 3 letters [RIP], so tired of losing friends to something as senseless as a drug overdose. WAKE UP people.”

Johnson was arrested in November for allegedly stealing from the house of her former girlfriend Jasmine Lennard.

She leaves behind her daughter Ava, who she adopted from Kazakhstan in 2007. The child was at the centre of a custody battle between Johnson and her parents.