The convicted murderer and former "Blade Runner" Paralympian Oscar Pistorius has been injured during a fight in prison over the use of a public phone, according to a South African prison official.

The double amputee, who is serving a 13-year jail sentence, was left with bruising after the altercation, the Department of Correctional Services said.

“Oscar Pistorius sustained a bruise following an alleged incident with another inmate over the use of a public phone in the special care unit where both offenders are detained at Attridgeville correctional centre,” Singabakho Nxumalo, a prison spokesman, said.

The South African sprinter underwent a medical exam and an investigation has been launched.

Reports in South African media suggested fellow inmates had become angry about the length of a call he was making using the prison's public telephone.

"As standard operating procedure regarding cases of alleged assaults‚ Department for 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," Mr Nxumalo added.

Pistorius shot and killed his girlfriend Reeva Steenkamp in the early hours of Valentine's Day in 2013.

The London 2012 gold medal winner claimed he had mistaken her for a burglar before firing through the locked door of his toilet four times.

Oscar Pistorius: Judge announces double prison sentence for murder of Reeva Steenkamp

He was arrested the same day and later convicted of manslaughter, which was subsequently replaced with a murder conviction by the Supreme Court.

Last month a South African appeals court doubled his sentence from six to 13 years.

In August 2016 Pistorius was treated in hospital after sustaining injuries while in prison.

Mr Nxumalo said at the time that the Paralympian had told officials he suffered injuries after falling out of bed.

One local report said Pistorius had injuries to his wrists, prompting the prison spokesman to say the athlete had "denied speculations of a suicide attempt".