Jeffry Picower, who was accused of earning $7.2 billion from Madoff's Ponzi scheme, drowned at his home in Palm Beach, Florida on Sunday (25Oct09).
The businessman, 67, was found unconscious in the pool and was later pronounced dead at a local hospital.
Picower was a key investor with Madoff, who was jailed for 150 years in June (09) after pleading guilty to siphoning billions of dollars from his wealthy clients, including Kevin Bacon and Kyra Sedgwick, John Malkovich, and Zsa Zsa Gabor.
Officials responsible for liquidating Madoff's investment company were in the process of suing Picower for the return of $7.2 billion they believe were profits from the Ponzi scheme.
Police in Florida have launched a probe into the businessman's death.