Carl Pistorius stands accused of culpable homicide - similar in gravity to the charge of manslaughter in the UK - over the death of a female motorcyclist in a traffic accident. The charges date back to an incident in 2010, but have only just emerged.
He is due to face trial in March, three months before his younger brother Oscar goes to court over the alleged murder of his model girlfriend Reeva Steenkamp.
Carl was ever-present at his brother's bail hearing last week, with magistrate Desmond Nair ultimately choosing to award the Paralympic and Olympic athlete bail for £74,000.
Lawyer Kenny Oldwage said in a statement from the family: "There is no doubt that Carl is innocent and the charge will be challenged in court.
"Blood tests conducted by the police at the time proved that he had not been under the influence of alcohol, confirming that it was a tragic road accident after the deceased collided with Carl's car,"
Photo: Oscar Pistorius' brother Carl hugs his father Henke during a break in court proceedings at the Pretoria Magistrates court, February 21, 2013
Meanwhile Oscar Pistorius spent his first night under bail conditions at his uncle's home on Saturday.
The Sunday Independent newspaper in South Africa tried to speak to the 26-year-old at his new address with uncle Arnold Pistorius, where Pistorius will remain as part of the terms of his bail.
"Hello, this is Oscar speaking," Pistorius began, before refusing to take any questions and handing the phone across to his uncle.
The paper reported that he sounded 'dejected'.
A spokeswoman for the sprinter, Lunice Johnston, said that Pistorius was in mourning over the death of Steenkamp and had sent her family a bouquet with a hand-written note.
"Oscar and his family are relieved bail has been granted," Johnston said, "but they are still grieving the loss of Reeva. Oscar spent time with his family last night at his uncle’s house in Pretoria.
"He respects their [the Steenkamp family's] time to mourn. Oscar and the Pistorius family feel it’s a private and personal matter between the two families.
"On Monday, two bouquets of flowers were delivered by a relative to Reeva's family, one from Oscar and one from the Pistorius family with hand-written notes. His management team also sent a bouquet."
Photo: Oscar Pistorius in magistrate's court, February 19 2013 - his brother Carl can be seen, bottom left (Reuters)