Carl Pistorius is charged with culpable homicide in the death of a motorcyclist in 2008; the case is unrelated to the Valentine's Day shooting of his younger brother's girlfriend.
However, it was not widely known of until a local television station reported it yesterday. A family statement said Carl appeared before a judge on Thursday and would be in court again in late March. His younger brother was freed on bail on Friday after a week of hearings.
Carl Pistorius declined to comment as he entered the home of an uncle in Pretoria yesterday. The house is where Oscar, 26, has been staying since being granted bail on Friday until his trial for the premeditated murder of model Reeva Steenkamp.
The family statement quoted lawyer Kenny Oldwage as saying: "There is no doubt Carl is innocent and the charge will be challenged in court. Carl deeply regrets the accident.
"Blood tests conducted by the police at the time proved he had not been under the influence of alcohol, confirming it was a tragic road accident after the deceased collided with Carl's car."
The family statement said charges had at one stage been withdrawn but then reinstated.
Carl Pistorius attracted little publicity until the arrest of his younger brother propelled the family into the glare of a global media spotlight.
He and their younger sister Aimee and father Henke appeared in court to support Oscar, who denies the charge, saying he believed he was shooting at an intruder.
On Saturday, Steenkamp's father said that if Oscar Pistorius was telling the truth about mistakenly opening fire then "maybe I can forgive him one day". However, he added that if the track star were lying "he will have to live with his conscience".