South African prosecutors admitted late Wednesday they were no longer sure that a substance found at Olympian Oscar Pistorius's home was in fact testosterone, rowing back on dramatic court testimony hours earlier.
"We can't tell what it is," said national prosecuting authority spokesman Medupe Simasiku. "We can't confirm or deny it until we get the forensic report."
A police witness for the prosecution earlier said at Pistorius's bail hearing that they had found "two boxes of testosterone and needles and injections."
Investigating officer Hilton Botha said the substance was found in a dresser in the athlete's bedroom by police investigating the murder of Pistorius's girlfriend Reeva Steenkamp on Valentine's Day.
Testosterone is on the list of substances banned by the International Olympic Committee.
But Pistorius's defence lawyer Barry Roux said the substance was in fact a legal herbal remedy.
"It's a herbal remedy and he can use it and he has used it before."
Craig Spence, a spokesman for the International Paralympic Committee, said Pistorius was tested twice during the London Paralympics in 2012 and tested negative.
At the games he won gold in the 400m, silver in the 200m and came fourth in the 100m.
The state's admission caps a difficult day for prosecutors who are trying to prove that Pistorius is guilty of premeditated murder and should not be granted bail.