In the wake of complaints by law professor Alan Dershowitz and others, the National Jewish Democratic Council has abruptly withdrawn a petition calling on Republican presidential nominee Mitt Romney to refuse “tainted money” from the world’s 16th richest man, Sheldon Adelson.

Mr Adelson, 78, a major donor to Jewish causes, has come under fire recently for allegedly condoning prostitution at his luxury gambling resorts in Macau, China. These charges, levelled by a disgruntled former employee whom Mr Adelson fired, were taken up with alacrity by Jewish Democrats who have become increasingly concerned about the millions of dollars that Mr Adelson has poured into support for Republican candidates.

In addition to Prof Dershowitz, who is a Democrat, the Jewish Federations of North America, Anti-Defamation League, and the Republican Jewish Coalition all decried the use of unproven claims to smear Mr Adelson’s reputation.

Sheldon Adelson, born in Boston to a poor Jewish family, was a Democrat who turned Republican when he began objecting to the taxes that he had to pay. He bought the Sands Hotel in Las Vegas in 1989, and has made his fortune both in the gambling business and through the founding of computer tradeshows.

Following the withdrawal of the petition,Mr Adelson announced a $5 million donation to the Young Guns Action Fund, a political action committee supported by House Majority Leader Eric Cantor, the highest-ranking Jewish member of Congress.