Vijay Singh acknowledged earlier this year that he had used a banned substance, but he will not be penalized by the PGA Tour as a result.
Singh, 50, was told Tuesday by commissioner Tim Finchem before a practice round for the Wells Fargo Championship that he would not face sanctions for taking a deer-antler spray after the World Anti-Doping Agency (WADA) determined its use was no longer considered prohibitive.
The three-time major champion's case was subsequently dropped, Finchem said at a news conference, because WADA no longer considers the substance to be prohibited unless a positive test for 1GF-1, a growth factor, results from taking it. Singh did not test positive for the banned substance found in the spray.
"Based on this new information, and given WADA's lead role in interpreting the prohibited list, the tour deemed it only fair to no longer treat Mr. Singh's use of deer-antler spray as a violation of the Tour's anti-doping program," Finchem said.
Singh contended that he didn't know the spray contained a growth hormone. He was sanctioned by the tour on Feb. 19 for admitting its use, but the tour does not administer blood tests -- the only way to detect growth hormones -- as part of its routine regimen.
Singh appealed the sanctions and continued to play.
Earlier this week, former Tour player Greg Norman called for blood testing in the sport.