By TJ Strydom and Tanisha Heiberg

PRETORIA (Reuters) - Oscar Pistorius is a "broken" man who should not be jailed for the murder of his girlfriend Reeva Steenkamp, a psychologist told a court in South Africa on Monday, while a prosecutor said he has shown no remorse.

The 29-year-old Paralympic gold medalist, known as "Blade Runner" for the carbon-fibre prosthetics he wore when racing, faces a minimum 15-year jail term after his manslaughter conviction for the 2013 killing was upgraded on appeal.

The case has prompted a fierce debate in a country beset by high levels of violent crime against women. Some rights groups have said the white athlete has received preferential treatment.

Jonathan Scholtz, a psychologist called by Pistorius' lawyer Barry Roux, told the sentencing hearing that the athlete, who attended in a dark suit and at times sat with his head in his hands, was on medication for depression, anxiety and insomnia.

"One would describe him as broken. In my opinion his current condition warrants hospitalization," Scholtz said, noting that Pistorius was not in the right frame of mind to testify.

"Since 2013, he becomes traumatized when he hears the sound of gunfire," Scholtz said. "He never wants to touch a firearm again."

Prosecutor Gerrie Nel questioned Scholtz's assertion that Pistorius was not fit to testify, saying he had given a TV interview. The hour-long interview with Britain's ITV is due to air on June 24 at 2000 GMT.

Nel told the court Pistorius had shown no remorse for the murder, and that he only "feels sorry for himself".

Pistorius had had temper tantrums in jail and had once banged a table when he got upset with a nurse, Nel said, asking Scholtz why he ignored Pistorius' actions.

Scholtz said Pistorius may have acted violently as he was still adapting to prison and affected by medication.

"Why would you select only positive views for your report. I find that in your report you are biased towards the accused," Nel said, shortly before the court adjourned for the day.

Pistorius' lawyer Roux declined to comment on the day's proceedings, as did Steenkamp's family.

Scholtz said Pistorius had been assaulted once in jail but Nel rejected this, saying the complaint register in which Pistorius often raised issues had no report of such an incident.

Nel also disputed a claim by the psychologist that Pistorius was traumatized after he saw a prisoner who had hanged himself, saying it was unlikely that he could have seen the victim.

Luvuyo Mfaku, a spokesman for the National Prosecuting Authority, told Reuters its position was "to argue for the prescribed sentence to be imposed, that is 15 years."

SUPPORTERS PROTEST

Johannesburg-based lawyer and legal analyst Ulrich Roux said the fact that Pistorius would not testify was crucial.

"I think it would have served them better to let him testify, and even if he breaks down, the state can take into consideration his frame of mind. In my opinion that's going to count against him," he said.

Pistorius was at first given a five-year sentence for culpable homicide, South Africa's equivalent of manslaughter, for shooting Steenkamp through a locked toilet door in his Pretoria home on Feb. 14 three years ago. He had argued he mistook her for an intruder.

The conviction was later upgraded to murder after an appeal heard by the Supreme Court, which ruled in March that Pistorius had exhausted all his legal options and could no longer appeal.

The original trial judge, Thokozile Masipa, started hearing the pre-sentencing arguments at Pretoria High Court on Monday.

State prosecutors who lodged the appeal say Pistorius intended to kill Steenkamp and that the law graduate and model had fled to the toilet during an argument. A final ruling on his sentence is expected by the end of this week.

Scholtz told the hearing, which was attended by Steenkamp's mother, that Pistorius had suffered financially and found asking others for assistance humiliating.

Pistorius lost millions of dollars in endorsements and sponsorships after reaching the pinnacle of his fame in London 2012 when he became the first double amputee to run in the Olympics, reaching the 400 metres semi-finals.

Outside the court, a group held up placards backing the athlete, one of them with the message: "Worldwide supporters of Oscar Pistorius".

Jacqueline Mofokeng, a spokeswoman for the Women's League of the ruling African National Congress party, which has attended the trial in support of Steenkamp, said: "I don't think he has remorse. We are calling for the 15 years without parole."

(Additional reporting and writing by James Macharia; Editing by Louise Ireland)