Pistorius in testosterone claims
Oscar Pistorius was embroiled in fresh controversy with prosecution claims that testosterone was found alongside needles in his bedroom.
Although his defence denied it and the claim pales into insignificance beside his murder charge, accusations of cheating would further diminish his standing.
His lawyer Barry Roux said the substance was actually a herbal remedy, Testocompasutium co-enzyme, and was not on any banned lists.
Confirmation is awaited on precisely what the substance is.
However, testosterone is banned in sport because it boosts strength and increases muscle mass and gives athletes faster recovery times.
In its various anabolic steroid forms - which can be administered orally, via injection or in a cream - it is outlawed globally by the World Anti-Doping Agency (WADA).
A spokeswoman for UK Anti-Doping, responsible for protecting UK sport from doping, said it was a violation to be found in possession, using, trafficking or administering performance-enhancing substances.
If any evidence emerged that the defendant, dubbed Blade Runner because of his prosthetic carbon fibre legs, did possess testosterone and was using it for some time he would face an investigation and the possible stripping of his 2012 Paralympic medals.
The International Paralympic Committee tested Pistorius during the Paralympics and found no drugs in his system, it was reported.