Joshua John Ravindran had said that he bashed his father with a baseball bat in a fit of grief and shock after finding him hanged.
He always maintained he found his father, Ravi Ravindran, 48, hanging from a beam in his Blue Mountains home on April 23, 2011, the Australian reported.
Joshua Ravindran's version of events was accepted by Justice Stephen Campbell in the Supreme Court in Sydney today.
The judge handed down verdicts of not guilty of murder and not guilty of manslaughter following a judge-alone trial.
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Ravindran threatened to move out of the family home during an argument the night before his father died. The judge said he was satisfied this left open the possibility that Ravindran's father had taken his own life.
Justice Campbell said: "The deceased had based his whole life around his son.
"The accused's decision was a direct attack upon his ego. Morbid jealousy is an aspect of the deceased's personality." Mr Ravindran was accused of murdering his father by bashing and strangling him in a bedroom of the family house, and then making it look like suicide.
The court heard medical evidence that the man's heart was still beating when the blows were inflicted.