Former Indianapolis developer Sydney “Jack” Williams has pleaded guilty to failing to report millions of dollars he received in commissions related to a Florida investment scheme.

Williams, of Naples, Fla., the founder of local retail-center development firm Williams Realty Group, entered his plea before a federal judge on Tuesday. The charge of subscribing to a false tax return carries a maximum penalty of three years in prison and a fine of $250,000. Sentencing is set for Jan. 12.

Williams, 63, admitted to failing to report $6.4 million in income from 2004 through 2007 that he earned from Miami Beach, Fla.-based Capitol Investments USA.

Its CEO, Nevin Shapiro, a year ago pleaded guilty to money laundering and securities fraud in what authorities called a $900 million Ponzi scheme. He was sentenced in June to 20 years in prison.

According to court papers, Williams earned a 10-percent commission on loans to Capitol from a group of Indiana and Florida businesspeople who believed they were investing in a Florida grocery-wholesaling business.

Many of the loans came from friends Williams met when he was a Sigma Chi at Ball State University .

Williams, who personally invested more than $10 million in the scheme, received more than $12 million for recruiting more than 60 people who invested $307 million with Capitol, according to a government press release.

Williams, however, was unaware that Shapiro or Capitol was engaged in fraud, the government said.

It’s not clear where all the money went. But in a jailhouse interview with Yahoo Sports this past summer, Shapiro said he lavished millions of dollars in impermissible benefits on University of Miami football and basketball players over nearly a decade.

Among the Hoosier investors were Charles Brown, a principal in Indianapolis-based Southern Bells Inc., one of the nation’s largest Taco Bell franchisees; and prominent local attorney James R. Fisher, a former Ice Miller partner and principal in Indianapolis-based law firm Miller & Fisher LLC.

Brown was among about a half-dozen investors who hired attorneys to oppose a settlement from a bankruptcy trustee liquidating Capitol. The trustee sued Williams for $115 million last year, charging he “knew or should have known” the business was a fraud.

The trustee later agreed to settle for just $334,000, after concluding Williams had few remaining assets. A federal judge initially rejected the deal but signed off this month after the parties agreed to remove language that would have barred Brown and dozens of other creditors from pursuing claims against Williams.