Death of wild-child socialite under investigation

Experts began tests today in a bid to discover how US socialite Casey Johnson died at just 30.

Johnson, an heiress to the Johnson & Johnson fortune, lived the life of a Hollywood socialite – partying with Paris Hilton, posing for the paparazzi, becoming engaged to bisexual reality TV star Tila Tequila and, like her idol Marilyn Monroe, dying young.