Kirk Jones, who famously survived going over Niagara Falls in 2003, died in another attempt over the famous waterfall weeks ago.
Jones' body was found earlier this week in Lake Ontario by a fisherman.
New York State Park Police Detective Sgt. Brian Nisbet said it appears Jones was in the Niagara Falls area April 19. On that day, crews responded to a report of a large "spinning ball" in the rapids.
Nisbet told Syracuse.com that the 10-foot ball went over the falls and was recovered, without a person in it, by a Maid of the Mist boat.
After an investigation, Nisbet said it's believed Jones was attempting to go over the falls inside the ball. However, he fell out at some point, which resulted in his death. The incident is still under investigation.
When Jones went over the 173-foot waterfall in 2003, he became the first to take the mighty plunge wearing only his clothes.
On his first attempt, a witness said Jones went over the edge with his hands over his head before plunging into the water below. The same witness said he then saw Jones pull himself onto rocks down below. He then floated across the U.S.-Canadian border on his back.
Before his initial jump, Jones spoke repeatedly about making a jump from the top, friends and family said.
Syracuse.com said Jones paid a $3,000 fine after pleading guilty to unlawfully performing a stunt for his first attempt.
At the time, Jones said he was trying to kill himself, Syracuse.com reported. However, he later said he was happy to be alive and asked "that no one ever try such a horrible stunt again."
Rick Hampson of USA TODAY and the Associated Press contributed to this article.