PRETORIA, South Africa (AFP) — Oscar Pistorius “ruined our whole family” when he killed Reeva Steenkamp, a South African court heardyesterday, as prosecutors turned the spotlight firmly back on the victim in a last-ditch attempt to secure a prison sentence for the Paralympic athlete.

After six months of evidence centred on Pistorius and last year’s Valentine’s Day shooting, Steenkamp’s family had their day in court, painting a picture of a thoughtful, caring young woman whose death felt like “the end of the world”.

Acting as a witness for the prosecution, Steenkamp’s cousin Kim Martin gave heartfelt evidence about the slain model’s journey from “fun-loving child” to victim of a tragedy that “ruined our whole family”.

With the clock ticking down to Pistorius’s judgement day, Gerrie Nel and his legal team are battling to scupper arguments that the double-amputee athlete should only carry out community service for shooting dead his girlfriend after he said he mistook her for an intruder.

Pistorius, 27, was found guilty last month of culpable homicide over the killing of the 29-year-old law graduate, but was acquitted of murder.

In yesterday’s sentencing hearing, Nel warned that justice itself was on trial and that if the star sprinter was seen to go free, South Africans would lose confidence in the legal system.

Slamming the defence’s suggestion of community service “shockingly inappropriate”, Nel warned that “if the court sentence is too light, and society loses trust in the court, they will take the law into their own hands”.

Judge Thokozile Masipa could issue a sentencing decision as early tomorrow, with her options ranging from a fine to 15 years in prison.

Nel yesterday sought to tip the scales of justice by putting the former model and reality TV star centre stage.

“I must be Reeva’s voice,” the cousin said, breaking down on the stand as she explained that Steenkamp’s parents had encouraged her to speak on behalf of their daughter.

“I had to do this for Reeva, I owe it to her.”

She recalled Reeva was the first baby she ever held, and recounted a joyful shared childhood filled with horse-riding, school homework and time with family.

Martin said the young Steenkamp once cared for a paralysed poodle named Jade that she carried around, serving as its “legs”.

As Martin recounted her cherished memories, Steenkamp’s father Barry, who suffered a near-fatal stroke after Reeva’s death, wept in court, his shoulders shaking.

Pistorius sat in the dock, also wiping away tears.

Martin said she was in a car when she heard on the radio that Pistorius had allegedly shot his girlfriend.

“I remember saying to my husband: ‘I hope to God he’s cheating on Reeva.'”

But when Martin saw her distraught mother she knew it was not so. “For me it was the end of the world,” she told the court.

The defence has warned that a jail term would “break” the star sprinter — who inspired millions when he became the first double amputee to compete in the able-bodied Olympics — and that he could fall victim to prison violence, including gang rape.

“Without legs he will be vulnerable and a lot more vulnerable than the normal man,” said probation officer Annette Vergeer.

The athlete admits that he shot Steenkamp four times through a bathroom door at his upmarket Pretoria home, saying he mistakenly believed she was an intruder.

Earlier Wednesday lawyers for Steenkamp’s family expressed shock that Pistorius’s defence team revealed details of secret “blood money” payments in court.

Pistorius had reportedly offered the family a one-off payment of nearly $35,000, which had been rejected, but had given them $540 a month.

In a statement on behalf of Steenkamp’s parents, lawyers said they had “honoured” a request from the athlete not to reveal the payments.