Jack Wishna was found Tuesday at his Henderson home, Clark County Coroner Mike Murphy said.
The circumstances surrounding the 54-year-old's death were unknown. Foul play wasn't suspected, police spokesman Keith Paul said.
The well-known wheeler and dealer will be remembered for orchestrating a multimillion-dollar agreement between performer Wayne Newton and the Stardust casino, said Dan Wilinsky, a spokesman for Wishna's latest project.
In a statement Wednesday, Newton called Wishna a longtime friend, and said his death came as a tremendous surprise.
Wishna is credited with bringing Trump and Treasure Island owner Phil Ruffin together to build the Trump International Tower in Las Vegas, and he was instrumental in persuading Jackson to return from his extended stay abroad in the mid-2000s, said Randall Sullivan, author of "Untouchable: The Strange Life and Tragic Death of Michael Jackson."
Jackson, who had been castle-hopping in Ireland, came straight to Las Vegas from Dublin.
"Michael arrived in a private jet and Wishna and his wife were there to meet him," Sullivan said. "So that tells you that Wishna was the guy in Michael's life at the time.
"They were thinking the front would be a set of flashing lights, a picture of Michael Jackson," Sullivan said.
Wishna had recently been developing a social media website for musicians and their fans. He had billed the site RockCityClub.com as a new way to discover talent and create rock stars.
Wishna is survived by his wife, Donna.
Associated Press writer Michelle Rindels contributed to this report.