Mr. Clifford, once Britain’s highest-profile publicity agent, was serving an eight-year sentence for assaulting woman and girls as young as 15.
Max Clifford, once the highest-profile public relations agent in Britain, died on Sunday in a hospital after collapsing in the prison where he was serving an eight-year sentence for sexual offenses against victims as young as 15.
His death was announced by the Ministry of Justice, and local media outlets reported that Mr. Clifford, 74, had collapsed twice at Littlehey Prison in Cambridgeshire and suffered a heart attack .
He was found guilty in 2014 of eight indecent assaults on women and girls between 1977 and 1985.
“As with all deaths in custody there will be an investigation by the independent Prisons and Probation Ombudsman,” a spokesman for Britain’s Prisons Service said. “Our condolences are with Mr. Clifford’s family at this difficult time.”
Mr. Clifford was the first person convicted as a result of Operation Yewtree, a British police investigation begun after it emerged that the entertainer Jimmy Savile had been a serial sexual predator for years. Mr. Savile died in 2011.
Police officers questioned many current and former celebrities over accusations of abuse dating back years, and several other prominent figures were jailed .
As a publicist, Mr. Clifford represented a roster of world-famous clients including both Muhammad Ali and O. J. Simpson. But he made his name from scandal, shepherding exposés of extramarital affairs that brought down at least one British government minister and filled the pages of tabloid newspapers in Britain and elsewhere for decades.
At least one of those newspapers, the Rupert Murdoch-owned News of the World, hacked into his cellphone voice mail in search of further secrets. The newspaper was later shuttered over its use of such hacking.
“For every story I break, there’s 10 I stop,” Mr. Clifford told The New York Times in a 2006 interview, explaining that his rule for celebrities seeking his help to avoid a scandal was that they had to tell him everything.
“I say, ‘Look, if I don’t know more about you than your wife, your husband, your mistress, your lover, I can’t do what you want me to, so there’s no point in your paying me fortunes and wasting your money and my time.’ ”
Mr. Clifford grew up in Surrey, in southern England, the son of an electrician and a former maid, and he started his own company at the age of 27. Before that, he said, he worked as a newspaper reporter and then at the record label EMI, where he helped to promote the Beatles, though the extent of his role with the band has been disputed.
“I’ve created false images for people all my life,” he told The Times in 2006. “I’m quite happy to make up stories about someone to create an image.”
