By Nick Butler

A social worker disputed suggestions Oscar Pistorius is "acting" on the latest day of his murder trial ©AFP/Getty ImagesOscar Pistorius was not "putting on a show" and seemed genuinely heartbroken, a social worker who helped the six-time Paralympic champion in the immediate aftermath of the death of girlfriend Reeva Steenkamp testified today.

The South African shot Steenkamp multiple times through a bathroom door on Valentine's Day last year after, he claims, mistaking her for an intruder in their Pretoria home.

There have been accusations the 27-year-old, who also competed at the London 2012 Olympic Games over 400 metres, has been "taking acting classes" and that his tears in court may not be real.

But after reading these reports, social worker and probation officer Yvette van Schalkwyk insisted Pistorius "cried 80 per cent of the time" when she assisted him at his first court appearance in February 2013. 

"What I saw from the first time I saw he was a man who was heartbroken... he cried, he was in mourning, he suffered emotionally," she reported, as the trial resumed today following a day's adjournment for the South African General Elections.

Van Schalkwyk added that when she sat with Pistorius in the cells at the time of his initial court hearings he vomited twice and told her he shot Steenkamp accidentally.

She denied feeling sorry for Pistorius but admitted that "after 24 years in probation you've got empathy, there's a difference".

Prosecutor Gerrie Nel disputed the importance of this evidence because it did not relate directly to the charges.

Judge Thokozile Masipa turned down these objections, pointing out that Nel had earlier questioned the Paralympian's sincerity.

Oscar Pistorius leaving court at the end of the day following the resumption of the trial today ©AFP/Getty ImagesOscar Pistorius leaving court at the end of the day following the resumption of the trial today ©AFP/Getty Images

Meanwhile, on what was a good day for the defence, anaesthetist Christina Lundgren cast doubt on prosecution claims that Pistorius had a late night argument with Steenkamp before he shot her.

This came after state pathologist Gert Saayman previously testified that food found in Steenkamp's stomach had been eaten no more than two hours before she was shot dead at 3am, thus corroborating with claims she was awake when neighbours testified hearing a women's voice arguing at the same time.

But Lundgren said the prosecution case that her stomach should have been empty if Pistorius was telling the truth, was "purely speculative".

She explained that before surgery patients are typically told not to eat for six hours to ensure their stomachs are empty, and that some ingredients in a chicken stir-fry Steenkamp reportedly ate, such as vegetables and fatty foods, could take longer to digest.