Hundreds of people across the country stand to lose millions of dollars in what investigators describe as a Ponzi scheme based out of a Fresno equipment-leasing company.

And the man FBI agents believe masterminded it all -- John W. Otto, a pioneer in the equipment-leasing industry -- committed suicide this week in Palm Desert.

His death complicates what investigators say will be an enormous task: tracking down where all the money went, and whether others in Otto's firm -- HL Leasing -- were involved.

FBI agents began looking into Otto and HL Leasing after investors complained that they had not received April interest payments on their investments with the firm. As many as 1,200 victims nationwide could lose the money they entrusted to Otto, investigators say.

"At this point, it does appear to be a Ponzi scheme," said Steve Dupre, an FBI spokesman in Sacramento. "Right now, from our preliminary review, it appears that $138 million is the potential loss in this case."

A Ponzi scheme typically involves using money from new investors to pay earlier investors. A notable example is the multibillion-dollar scam by Wall Street businessman Bernard Madoff that surfaced last fall.

About 200 to 300 victims are from the Fresno area, Dupre said.

At the West Shaw Avenue office building HL Leasing shared with another Otto enterprise, Heritage Pacific Leasing, the doors are locked, the blinds are drawn tight and the lights are out.

"Due to the untimely death of Mr. John Otto, CEO of HL Leasing, the offices are closed until further notice," reads a sign taped to the door.

Otto, 67, died Monday from a self-inflicted gunshot wound to the head, said Scot Collins, a lieutenant with the coroner's bureau of the Riverside County Sheriff's Office.

Collins said Otto shot himself about 3 p.m. in the parking lot of the Palm Desert Visitors Center. The parking lot is only a few miles from Otto's $1.98 million home near Ironwood Country Club's North golf course.

While he lived in Palm Desert, Otto headed several leasing and financial businesses headquartered in Fresno.

Otto's death came only days after his attorney sent a letter May 8 to investors asking for their patience. Investors who had entrusted their money with Otto said their first inkling of trouble was when their payments didn't arrive as scheduled on April 25. Some of them contacted Fresno lawyer Donald Fischbach.

Fischbach set up a conference call for investors on Wednesday to figure out what to do. He was expecting 15 or 20 investors, but about 90 joined the call. Since then, more than 200 people have contacted his office, he said.

He knows of people who invested anywhere from $40,000 to $1.7 million.

The godfather of leasing

Otto was a legend in the equipment-leasing industry, said Tom McCurnin, a Los Angeles lawyer who specializes in the business.

"He was one of the godfathers of California leasing," he said. "He was a mover and shaker for the last 20 years."

The leasing industry matured in the late 1980s and 1990s as an alternative to traditional financing. Businesses could lease equipment for five years and write off part of the expense.

"It became a different way to finance equipment," said McCurnin, an attorney with the firm of Barton, Klugman and Oetting. "Prior to that, people got a bank loan to buy computers or they saved up and bought it."

Investors said Otto told them their investments were backed by leases Otto purchased from American Express, the financial-services giant best known for its credit cards.