Scottsdale, AZ (Sports Network) - Vijay Singh admitted on Tuesday that he used deer antler spray, a banned substance under the PGA Tour's Anti-Doping Policy.

After his name was included in a "Sports Illustrated" story about S.W.A.T.S., - Sports with Alternative to Steroids - "a two-man company run out of a gym near Birmingham," Singh released a statement:

"In light of the recent article on sportsillustrated.com, I want to issue the following statement:

"While I have used deer antler spray, at no time was I aware that it may contain a substance that is banned under the PGA Tour Anti-Doping Policy. In fact, when I first received the product, I reviewed the list of ingredients and did not see any prohibited substances. 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. I will not be commenting further at this time."

"Sports Illustrated" reported that Singh paid S.W.A.T.S. $9,000 for the spray and various other products.

The tour notified players that the deer antler spray had been implicated in a positive drug test. According to the article, golfers were made aware of the spray's nature in 2011.

Singh, who turns 50 in a month, has long been one of the most physically fit players in golf. He has at times been a lightning rod for controversy, but this may reach another level.

The only player suspended by the PGA Tour for a banned substance was Doug Barron. He received a one-year suspension due to a failed drug test for elevated levels of testosterone.

Singh has not failed a drug test, so what the tour can do as to suspending Singh remains to be seen.

Singh is still in the field this week for the Phoenix Open.