Oscar Pistorius suffered a bruise but was not seriously hurt during an alleged assault in prison last week, a spokesperson for South Africa's Department of Correctional Services (DCS) has confirmed.
The former Olympic and Paralympic sprinter is serving a sentence, increased last month to 15 years, minus time already served, for killing his girlfriend Reeva Steenkamp in 2013.
Having initially been convicted of culpable homicide, Pistorius' conviction was upgraded to murder in 2016 and his sentence increased by a Supreme Court of Appeal judgement in November.
According to DCS spokesperson Singabakho Nxumalo, Pistorius was allegedly involved in an altercation over the use of a public phone.
"The Department of Correctional Services (DCS) confirms that inmate Oscar Pistorius sustained a bruise following an alleged incident of assault that occurred last week on 06 December 2017," the statement read.
"It is alleged that he was involved in an altercation with another inmate over the use of a public phone in the special care unit where both offenders are detained at Atteridgeville Correctional Centre. No serious injuries were reported.
"As a standard operating procedure regarding cases of alleged assaults, DCS has launched an internal investigation into the matter to establish the facts and to ensure that appropriate action is taken as incidents of assaults are not allowed.
"The DCS is committed to ensuring the safety of offenders, officials and service providers at all times and therefore any form of violence in the correctional centres is dissuaded."