The PGA Tour has cleared three-time major winner Vijay Singh of doping offences after the World Anti-Doping Agency confirmed the deer antler spray the Fijian admitted to using was not "prohibited unless a positive test results".
Singh initially came under scrutiny in January after revealing in an interview with Sports Illustrated to using the spray.
Deer antler spray contains a banned performance-enhancer connected to human growth hormone.
The 50-year-old stood by his comments in a statement but added: "At no time was I aware that it may contain a substance that is banned under the PGA Tour Anti-Doping Policy."
As a result, he was then sanctioned by the PGA Tour, who then contacted WADA to discuss the issue after Singh appealed.
"During the appeal process, PGA Tour counsel contacted WADA to confirm a number of technical points," said a statement on the PGA Tour's official website.
"At that time, WADA clarified that it no longer considers the use of deer antler spray to be prohibited unless a positive test results.
"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."
IGF-1 - the controversial substance found in deer antler spray - is listed on both the WADA and PGA Tour prohibited lists, although there is currently no test available for detecting it in routine blood testing.
While the PGA Tour, who warned professionals over the use of deer antler spray in August 2011, viewed an admission of using a banned substance as a violation of their policy, it was happy to take no further action with Singh after consulting WADA.
The PGA Tour has reminded Singh and his fellow professionals of their future conduct, however.
"Since his initial quote was made public, Mr Singh has co-operated with the Tour investigation and has been completely forthcoming and honest," the statement said.
"While there was no reason to believe that Mr Singh knowingly took a prohibited substance, the PGA Tour Anti-Doping Programme clearly states that players are responsible for use of a prohibited substance regardless of intent.
"In this regard, Mr Singh should have contacted the PGA Tour Anti-Doping Programme administrator or other resources readily available to players in order to verify that the product Mr Singh was about to utilise did not contain any prohibited substances, especially in light of the warning issued in August 2011 in relation to deer antler spray."
The statement added: "Going forward, the PGA TOUR is committed to increasing its educational initiatives to remind players of the PGA TOUR Anti-Doping Program and the risk of utilising any product without a full understanding of the ingredients contained in that product."