An investment fund with ties to Bernard Madoff is emerging as a central player in helping the financier raise billions of dollars worldwide, extending the reach of an alleged Ponzi scheme.

The Securities and Exchange Commission, as part of an investigation into Madoff's activities, determined in 2006 that the fund, Fairfield Greenwich, hadn't properly disclosed that Madoff oversaw its investment decisions, according to an SEC document, though the agency found no evidence of fraud.