Pistorius emotionally devastated - therapist

Oscar Pistorius arrives in court. Photo / AP

Oscar Pistorius exhibited deep remorse and was emotionally devastated after the death of his girlfriend, Reeva Steenkamp, the athlete's therapist has told the North Gauteng High Court.

Psychologist Lore Hartzenberg was testifying at the sentencing hearing of the South African double-amputee Olympic sprinter for the killing of Steenkamp.

Pistorius shot her dead through a bathroom door in his Pretoria home on February 14, 2013.

Judge Thokozile Masipa on September 12 accepted the athlete's version of the events - he had testified that he mistook Steenkamp for a burglar - and found him guilty of manslaughter. The trial is now in the sentencing phase.

Pistorius had planned a future with Steenkamp, paying a deposit on a house he wanted to share with her, Hartzenberg told the court.

Therapy sessions with the athlete often had to be interrupted because of his incessant weeping, the psychologist testified.

At the same time as Pistorius was grieving for "the loss of someone he loved," he was "often overwhelmed by feelings of guilt or remorse," while he "questioned God's grace and forgiveness," Hartzenberg said.

She said the athlete was very concerned about the Steenkamp family and frustrated by the impossibility of communicating with them.

Not being able to attend Steenkamp's funeral left him with unresolved grief, Hartzenberg said.

The question of whether Pistorius felt remorse could influence the sentence issued by Masipa.

The athlete also had to cope with being "vilified and humiliated" in the media and on social networks, leaving him feeling "utterly worthless, devastated and guilt-ridden," Hartzenberg said.

"We are left with a broken man who has lost everything," the therapist said.

Pistorius has been diagnosed with post-traumatic stress disorder, Hartzenberg said, explaining he remained under anti-depressive medication and would continue requiring "intensive" therapy.

An anxious-looking Pistorius made no comments to reporters when entering the court building in Pretoria. The number of scanners had been increased following alleged threats to Pistorius' life, broadcaster eNCA reported.

The defence was expected to call two more witnesses, while the prosecution said its plans were not yet clear. Prosecutor Gerrie Nel said the hearing was likely to conclude this week.

Masipa will then issue her sentence, which could range from a fine to a jail term of up to 15 years.

Pistorius did not mean to kill anyone, but acted negligently and unreasonably, knowing there was someone in the toilet with little room for manoeuvre when he fired the shots, the judge said in her September decision.

The verdict sparked an outcry, with many saying Pistorius intended to kill and should have been found guilty of murder.

National Prosecuting Authority spokesman Nathi Mncube said on Monday that the state would seek "the harshest sentence possible."

"Somebody lost a life and we think that deserves the harshest sentence," Mncube said.

- AAP