The credit rating agency that downgraded U.S. debt is reportedly the target of a federal investigation.
The New York Times reports the Justice Department is looking into whether Standard and Poor's rated dozens of mortgage securities improperly in the years leading up to the housing bust.
The Times says investigators want to know if S&P executives overruled analysts who wanted to award lower ratings, which could damage the belief that analysts act independently.
S&P and other ratings agencies made record profits during the housing boom by awarding high ratings on troubled mortgages, making them appear less risky.
The investigation was reportedly under way before S&P downgraded the country's credit rating.