Jupiter police Sgt. Scott Pascarella said Newton-John and her husband, John Easterling, were not in the house when the body was found, The Palm Beach Post reported. The man, 42, whose identity had not been released, was believed to be working for the couple as a contractor.
Pascarella said the man died of a gunshot wound. He said the death appeared to be a suicide but the investigation remained open.
Newton-John, 64, born in England and raised in Australia, is a four-time Grammy-winning pop and country singer. She starred with John Travolta in the movie version of "Grease."
Her house is in Jupiter Inlet Colony, a tiny upmarket coastal town. The house is reportedly under contract to Rosie O'Donnell, who recently sold her Miami mansion.