The U.S. Marshal Service is investigating whether a convicted hedge fund scam artist's apparent suicide jump is real or a lie designed to avoid prison time.

Samuel Israel III's SUV was found in the middle of Bear Mount Bridge around 12:30 p.m. Monday. The words 'suicide is painless' were scrawled in dust on the hood.

In April, a federal judge sentenced the 48-year-old co-founder and chief executive of the now-collapsed Bayou hedge funds to 20 years in federal prison for conspiracy and fraud. Israel was also ordered to pay $300 million to his victims. He was supposed to surrender to authorities in Ayer, Mass. at 2 p.m. Monday.

Helicopters and police boats swarmed the Hudson River near the bridge searching for Israel's body to no avail. Investigators say they have no evidence that he took the plunge.

"We have a very specific time of the vehicle arriving at that location and parking, but beyond that we have no other factual information with regard to a possible jumper," says New York State Police Senior Investigator Bruce Cuccia.

The FBI is "actively looking" for Israel. Ross Intelisano, who represents 20 investors who lost $25 million, says his clients don't buy the suicide. "Their comments to me are, 'Show me the body. I'll believe it when I see the body,'" Intelisano says.