Updated from 2:25 p.m. EDTCitigroup ( C) CEO Sanford Weill has spent an unusually scandal-free half-century on Wall Street, only to see his reputation repeatedly tarnished over the last 12 months. His latest troubles could be his most serious. Weill, who is known for being a demanding leader, is currently the target of an investigation by New York state Attorney General Eliot Spitzer, according to The Wall Street Journal. Spitzer is looking into whether Weill pushed telecom analyst Jack Grubman to upgrade shares of AT&T ( T) in April 2000 in order to win a lucrative investment banking deal. "Sandy Weill is very respected on the Street, so I think there's no doubt it will clearly hurt his reputation," said John Barrett, a financial analyst at Gannett, Welsh & Kotler. "This is the first time that I've seen anything like this come out against him specifically." A Citigroup spokeswoman denied the allegations. "Mr. Weill never told any analyst what to write and any suggestion that he did is outrageous and untrue," Christina Pretto said.