The 26-year-old is accused of murdering Reeva Steenkamp in the early hours of Valentine’s Day and will appear again in court on Tuesday.
The City Press newspaper claims police have asked for blood taken from Pistorius to be tested for steroids in anticipation that his defence team might claim he acted in "roid rage" – an aggressive condition associated with taking large doses of performance-enhancing drugs.
Numerous British newspapers and sources also cite a report from The Sun that claimed steroids were found at the Paralympian's home.
"Steroid drugs were found at Pistorius’s home together with evidence of heavy drinking. That’s why police have specifically ordered that he be tested for steroids," The Sun claims.
There has been no immediate comment from police regarding the reported discovery of steroids.
The mother of Steenkamp, June, has spoken to South Africa’s Times newspaper of her family's loss with "the most beautiful person who ever lived" having to suffer a "horrendous death".
"She loved like no one else could love. She had so much of herself to give and now all of it is gone," she said. "Just like that, she is gone. In the blink of an eye and a single breath, the most beautiful person who ever lived is no longer here.
"All we have is this horrendous death to deal with, to get to grips with. All we want are answers, answers as to why this had to happen, why our beautiful daughter had to die like this."
Steenkamp's uncle Michael said the family would focus on saying farewell to her.
"For now, we are just focusing on getting over the funeral... on getting this part of the difficult journey behind us," he said.
"We're trying not to think about Oscar or the court appearance. We have deliberately not watched TV or listened to the radio. We just don't want to think about it. We want to blank it all out and focus for now on the here and now."
Meanwhile, a friend of Pistorius told Afrikaans newspaper Beeld that the sprinter nearly shot him through the foot in a Johannesburg restaurant.
Kevin Lerena, a boxer and mutual friend of the couple, said he had been dining at Tasha's restaurant in Melrose with the couple and other friends when the gun went off by mistake as Mr Pistorius held it.
"I must emphasise that the gun belonged to one of Pistorius's friends. Oscar just wanted to look at the gun, and it sort of snagged on his pants, releasing the safety catch," he told Beeld. "A shot went off. I wouldn't call him negligent, it was just an accident.
"He apologised to me for days afterwards. I got a huge fright, because the bullet hit the ground just centimetres from my foot ... but it really was just a freak accident."
The restaurant's manager Jason Loupis said he did not report the incident to police. "I went to investigate when I heard the shot, but they all denied it," Loupis said.
Citing "sources close to the investigation", the City Press newspaper have also claimed that a blood-covered cricket bat "is the central piece of evidence in the unfolding murder investigation."
The paper claims that Steenkamp's skull had been "crushed", and that forensic tests are to be carried out to determine whose blood is on the bat.
Police are said to be investigating the possibilities that Steenkamp used the bat in self-defence, or that Pistorius used it to break down a door.