The flamboyant former model Anna Nicole Smith has died near Miami, Florida at the age of 39, her lawyer has said.
Ms Smith, a former Playboy bunny, married Texas oil billionaire J Howard Marshall II in 1994 when she was 26 and he was 89. He died a year later.
She spent years in court fighting his son for a share of his estate, and won a victory at the Supreme Court in 2006.
She was found unconscious in a hotel room and could not be resuscitated. An autopsy will be carried out later.
One of Ms Smith's lawyers told Reuters news agency her husband Howard K Stern was "speechless and grieving".
Her son Daniel, the product of a short-lived youthful marriage, died at the age of 20 in September, just days after Ms Smith's daughter was born.
The baby girl is the subject of a paternity suit, with Ms Smith's former boyfriend Larry Birkhead saying he is the father of the child.
He sued Ms Smith in Oct 2006, shortly after the baby was born.
Ms Smith said Mr Stern, who is also her lawyer, was the father of the child.
A former topless dancer, Ms Smith achieved considerable success as a model, she was named Playboy's playmate of the year in 1993 and secured a lucrative contract with Guess Jeans.
In 1994 she married the 89-year-old Howard Marshall II.
His death 14 months later triggered a feud with his family over the inheritance of his estate which saw Ms Smith make regular courtroom appearances in what became a protracted and bitter battle.
She also appeared in films including one of the Naked Gun movies.
From 2002 to 2004, she had her own reality TV programme, The Anna Nicole Smith show.
Ms Smith was born Vicki Lynn Hogan in Mexia, Texas, on 28 Nov 1967.