The former world golf number one Vijay Singh has denied knowingly using a substance that violated the PGA Tour's anti-doping policy, saying he's angry about the situation.
In a Sports Illustrated article, the Fijian was linked to a two-man company called Sports with Alternatives to Steroids and its deer antler spray that purportedly helps athletic performance.
The spray contains IGF-1, an anabolic hormone that boosts muscle growth, and is banned by all major sports organisations.
The 49 year old Singh admits to having used the spray but says he had no idea it violated PGA anti-doping rules.
He says he is co-operating with a PGA Tour investigation into the matter.