The charge related to a 2008 road accident, in which a woman motorcyclist lost her life, lawyer Kenny Oldwage said in a statement on Sunday, which was issued by Vuma Reputation Management.
"Following the accident culpable homicide charges were brought against Carl Pistorius but the charges were later withdrawn by the state," he said.
The National Prosecuting Authority's deputy public prosecutor later reinstated the charges.
Speaking on Carl Pistorius's behalf, Oldwage said the charge would be challenged in court. "Carl deeply regrets the accident," he said.
Blood tests conducted by the police at the time proved that he had not been under the influence of alcohol.
Carl Pistorius appeared in court on Thursday, the day before bail of R1-million was granted to his brother. The case was postponed until the end of March. The exact date could not be confirmed.
Oscar Pistorius is accused of killing his girlfriend Reeva Steenkamp at his home in Pretoria on February 14. The case has been postponed until June 4.