Mr Kain, who strangled his mother Beverly Kain after an argument in their Goulburn home on February 27, 2011, had pleaded guilty to manslaughter on the grounds of significant impairment.

The jury accepted this defence and returned the verdict after one day of deliberation.

Sydney Morning Herald journalist Stephanie Gardiner previously reported that Mr Kain had told the court he "freaked out" and strangled his elderly mother, after years of arguments about whether his smoking caused his father to die from oesophageal cancer.

The jury accepted the defence offered by Mr Kain’s barrister Peter Williams that at the time of Beverly Kain’s death, Mr Kain was impaired and had diminished capacity, in part as a result of brain damage and alcoholism.

Mr Kain will be sentenced at a later date.