The jailed South African track star suffered a bruise after he allegedly started a fight with another inmate in the prison where he is serving a sentence for murdering his girlfriend, a prison spokesman said on Tuesday.
Fellow prisoners were angered by a long phone call he made which lead to an altercation, which broke out at Atteridgeville Correctional Centre, near Pretoria, on December 6.
Pistorius could now also faces losing prison privileges such as access to the jail tuck shop or a ban on the phone which ironically started the fight.
The 31-year-old is still classified as a “low risk” inmate but may be re-classified if an investigation finds that he was the one that started the fight.
According to the jail, the other lag involved in the brawl is also detained on the special care unit “where inmates with special needs and different sexual orientation are held for their own protection”.
It is believed the two men “know each other well”.
Singabakho Nxumalo, a spokesman at the Department of Correctional Services, said: “Oscar sustained a minor bruise. It was so minor it didn’t need any form of treatment.
“As standard operating procedure regarding cases of alleged assaults, the Department of Correctional Services has launched an internal investigation into the matter to establish the facts and to ensure that appropriate action is taken as incidents of assault are not allowed.
“We want to know that proper security protocols were followed by prison staff.”
The Paralympian won six Paralympic gold medals and was known as the “Blade Runner” for his use of carbon-fibre prosthetics.
He was convicted for the murder of his girlfriend Reeva Steenkamp in 2013, after shooting her multiple times through the bathroom door of his home.
Pistorius is serving 13 years and five months after the Supreme Court last month more than doubled his sentence.
Atteridgeville only houses inmates who are serving a maximum of six years, and has upgraded facilities, including ensuite bathrooms for prisoners with special needs.
Today, Pistorius’s brother Carl posted an encouraging Winnie the Pooh-quote on Twitter after news of the brawl emerged, writing: “Always remember: You’re braver than you believe, stronger than you seem, and smarter than you think.”