Sunny von Bulow fell into a coma at her Rhode Island mansion in 1980
US heiress Martha von Bulow, who spent almost three decades in a coma but was still at the centre of 1980s courtroom dramas, has died at the age of 76.
Mrs von Bulow, known as Sunny, was found unconscious in her Rhode Island mansion in December 1980.
Her second husband, Claus von Bulow, who is now a society figure in Britain, was acquitted of twice trying to kill her with insulin injections.
The events were turned into a 1990 Hollywood film, Reversal of Fortune.
Starring Glenn Close and Jeremy Irons, the film was based on a book by Alan Dershowitz, the Harvard lawyer who defended Claus von Bulow at his second trial.
The daughter of utilities tycoon George Crawford, Sunny von Bulow died at New York's Mary Manning Walsh Nursing Home, her family said.
She is survived by a daughter from her marriage to Claus von Bulow, and two children from her first marriage to an Austrian prince.
The von Bulows had been celebrating just before Christmas 1980 when Sunny von Bulow - who was then 48 and had a history of drug-consumption and heavy drinking - was taken ill in a dazed state.
Doctors concluded she had suffered brain damage that left her in a "persistent vegetative state". Although she was kept alive on feeding tubes at an estimated cost of hundreds of thousands of dollars a year, Sunny von Bulow never regained consciousness.
Prosecutors claimed Claus von Bulow had injected his wife with insulin twice in an effort to inherit much of her fortune, and he was charged with two counts of attempted murder.
In what correspondents say was one of the most sensational legal cases of the 1980s, Claus von Bulow was at first convicted in 1982, before being cleared on appeal, and then acquitted at a second trial in 1985.
Two years later he agreed to divorce his wife and give up claims to her fortune of up to $40m, as well as the $120,000-a-year trust fund she had established for him.
Claus von Bulow currently lives in London, where he writes book reviews.