LONDON, Jan 18 (Reuters) - Former aide to Margaret Thatcher and ex-treasurer of Britain's Conservative Party, Alistair McAlpine, who was wrongly accused of child abuse in a BBC report that led to a major crisis at the broadcaster, has died aged 71, his family said on Saturday.
Prime Minister David Cameron led tributes to McAlpine, who, as a key fundraiser, helped secure Thatcher's three election triumphs that made her Britain's longest-serving leader in the 20th century.
"My thoughts are with Lord McAlpine's family - he was a dedicated supporter of Margaret Thatcher and the Conservative party," Cameron said on Twitter.
McAlpine largely disappeared from public view after Thatcher's fall from power in 1990 until a 2012 BBC report accused an unnamed "leading Conservative politician from the Thatcher years" of sexually abusing boys in the 1970s and 1980s.
McAlpine was widely named on the Internet as the subject of the report, which the BBC later admitted was wrong, sparking one of the worst crises in the British public broadcaster's 90-year history.
The scandal caused the then Director General George Entwistle to resign after the abuse victim central to the BBC investigation said McAlpine was not one his attackers.
The publicly-owned broadcaster paid 185,000 pounds ($304,000) to McAlpine, who also received damages from others who had reported the story.
In a closely-watched Twitter libel case, the wife of a British parliamentarian paid damages to McAlpine after a court ruled her tweet, "Why is Lord McAlpine trending? *Innocent face*", was defamatory.
Several other people with wide followings on Twitter, who had also repeated the false allegation, voluntarily settled out of court.
McAlpine, a property developer who was also a gallery owner and art collector, died peacefully at his home in Italy on Friday, his family said. (Reporting By Costas Pitas; Editing by Raissa Kasolowsky)