New Zealand golfing great Sir Bob Charles says he had no idea the health supplement he has taken and promoted for years contained a substance banned by the World Anti-Doping Agency.
Deer velvet products have come into the spotlight after Fijian golfer Vijay Singh admitted using deer antler spray, saying he was unaware it contravened golf's anti-doping rules.
The products contain the "insulin-like growth factor" IGF-1, which is on the World Anti-Doping Agency's 2013 prohibited list.
New Zealand company Silberhorn sells a wide range of deer velvet products, promoted by Sir Bob, the 1963 British Open champion, who has taken deer velvet for nearly 20 years.
He said he had been "totally unaware" that deer velvet contained any banned substances, and it had not been confirmed to him.