Oscar Pistorius is a
Dr Lore Hartzenburg revealed painful details about sessions with Oscar Pistorius in wake of Reeva Steenkamp's deathGetty

Oscar Pistorius's therapist has revealed details of harrowing sessions with the fallen idol and delivered a gloomy prognosis about his future.

Pistorius is now a convicted killer in the shooting death of Reeva Steenkamp and sentencing proceedings are under way in Pretoria, South Africa.

Dr Lore Hartzenburg said at the hearing that the former paralympian is a "broken man" who will never recover from the killing of Steenkamp.

Hartzenburg said it had wrecked his life by stripping him of his identity and he was plagued by the knowledge everything was his fault.

The mental health professional also singled out media coverage as having a detrimental effect upon the former runner's well-being. She identified a "plaform of abuse" by social media users which had been the cause of great pain for him.

Pistorius has post traumatic stress disorder (PTSD) relating to the killing.

Pistorius's defence team called Hartzenburg to testify at his sentencing hearing. In response to her testimony, prosecutor Gerrie Nel said: "We are dealing with a broken man, but he is still alive."

Speaking at North Gauteng High Court in Pretoria, Hartzenburg said: "[Pistorius] will require intensive and on-going psychotherapy. We are left with a broken man who has lost everything.

"He's lost his love relation, he's lost his moral and professional standing. He's lost his career and earning potential. He's unlikely to fully recover from the consequences of the shooting incident."

Pistorius, 27, still carries around photographs of Steenkamp, the court was told.

He also has "unresolved guilt and remorse" because he couldn't attend her funeral, and because of "the ever-present media focus upon him," Hartzenburg said.

"His fall from being an icon to being vilified had a profound effect on his sense of self. He experiences himself as utterly worthless, devastated and guilt ridden. This has resulted in a loss of identity," she told the court.

"As a world class athlete he had a platform to make a difference for other disabled people which meant a lot to him. He feels he has now lost his voice to make a difference to disadvantaged communities and children."

Nel pointed out Steenkamp's father Barry had suffered a stroke in the aftermath of her Valentine's Day death.

Sentencing hearings could last up to one week and Pistorius could yet escape a prison sentence if he is granted medical parole on account of his disability.