The 50-year-old Fijian admitted to American publication Sports Illustrated in January that he had used the substance, but maintained he was not aware that it was banned by the Professional Golfers Association (PGA) and the World Anti-Doping Agency (WADA).

"At no time was I aware that it may contain a substance that is banned under the PGA Tour Anti-Doping Policy," he said in a statement.

Earlier in the year, he had also said: "I am absolutely shocked that deer-antler spray may contain a banned substance and am angry that I have put myself in this position.

"I have been in contact with the PGA Tour and am cooperating fully with their review of this matter."

Singh was subsequently sanctioned by the PGA, who referred the case to WADA following an appeal from the golfer.

"During the appeal process, PGA Tour counsel contacted WADA to confirm a number of technical points," said a statement on the PGA Tour 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 programme."

2000 US Masters winner Vijay Singh has been cleared of doping despite admitting to using a banned substance

Despite warning players of using the spray in 2011, the PGA Tour has decided not to take further action against Singh following correspondence with WADA.

"Since his initial quote was made public, Mr Singh has cooperated with the Tour investigation and has been completely forthcoming and honest," read a statement.

However, the PGA reminded players that use of banned substances will not be tolerated under different circumstances, and sent a warning to players that may be knowingly or unknowingly using a banned substance.

"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," it continued.

"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.

"Going forward, the PGA Tour is committed to increasing its educational initiatives to remind players of the PGA Tour Anti-Doping Programme and the risk of utilising any product without a full understanding of the ingredients contained in that product."

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