Nicholas Bartha was pulled from the rubble of his four-story townhouse last week suffering severe burns. Police were unable to interview the 66-year-old before he died.
Ten fire-fighters and five other people were injured by the blast.
It’s thought he allowed gas to fill the house, causing the explosion which destroyed the A$8.5m building, rather than sell it as part of a divorce judgment.
Bartha had not been charged and "if he's dead, there's no criminality," said New York City police spokesman Detective John Sweeney.
Bartha faced a $5.3m divorce payment to his former wife and the house was to be sold at auction in October.
Cordula Bartha received an e-mail shortly before the explosion in which her former husband warned her she would be "transformed from a gold differ to an ash and rubbish digger".
"I always told you I will leave the house only if I am dead," the e-mail went on. You ridiculed me. You should have taken it seriously."
Neighbours are now suing Bartha's estate for damages they say were caused to their property by the explosion.