Prosecutors have dropped their case against an Adelaide man charged with murdering his father earlier this year.
Emergency services were called to Frank Russo's Paradise home, in Adelaide's north-east in the early hours of February 8.
Despite the efforts of paramedics, the 65-year-old independent research scientist was pronounced dead at the scene.
His son Joel Michael Russo, 36, who lived at the same house on Urban Avenue, was taken into custody and charged with murder later the same day.
Mr Russo was remanded in custody until last month when he was released on bail.
During a hearing in the Adelaide Magistrates Court, prosecutors withdrew the murder charge against him.
He was excused from attending the hearing.
The court previously heard Frank Russo suffered from a heart condition and that the possibility he had died from natural causes could not be ruled out.
After Mr Russo's first court hearing in February, his mother said the incident was a "huge shock".
