Griffin, 27, died after leaping from the roof of a bar in the Massachusetts town of Nantucket, last weekend.
According to the Boston Globe, the financier dived from the top of a bar called Juice Guys into the water, before surfacing once and then disappearing for good.
In the weeks before his untimely death, Griffin had seen the ice bucket challenge taken up by global figures, including Microsoft founder Bill Gates, Facebook founder Mark Zuckerberg and a host of celebrities including Oprah Winfrey, Lady Gaga and Justin Bieber.
The challenge has so far raised around $23m (£14m )in aid of Pete Frates
Only hours before his death, Griffin had raised $100,000 in aid of myotrophic lateral sclerosis, on behalf of his pal with the condition, Pete Frates.
Paying tribute to Griffin on Facebook, Frates wrote: “Helping out was nothing new for Griff. He held his own event for me back in 2012, just a few months after diagnosis.
“He worked his butt off these last few weeks for ALS. We texted everyday, planning and scheming ways to raise funds and plan events.”
Griffin had been delighted by the success of the ice bucket challenge, which has spread so much that Russian president Vladimir Putin was challenged to do it by movie star Vin Diesel.
Griffin’s father Robert told the Globe it made him “the happiest guy in the world”.
“He called me last night and told me he was in paradise,” said Griffin.