JEFFERSON CITY, Mo. -- Missouri's treasurer says the state's retirement account is among thousands of investors and financial institutions entangled in an investment scheme.

Bernard Madoff, the former chairman of the Nasdaq Stock Market, confessed last month to taking $50 billion in a Ponzi scheme.

Missouri Treasurer Clint Zweifel said Friday that includes $3.5 million from the Missouri State Employees' Retirement System. Those funds were placed with Seattle-based Silver Creek Capital Management, which then invested the money with Madoff.

Zweifel, who sits on the retirement system board, called Friday for a detailed review to check for additional exposure to Madoff's scheme.

The retirement systems' executive director, Gary Findlay, said the link to Madoff and lost funds were discovered late Monday. Findlay said the retirement system has already checked for exposure but that fraud is difficult to spot.