The NFL has sent letters to several players ordering them to cut ties with S.W.A.T.S., the company at the center of sports’ latest performance-enhancing substance controversy, ThePostGame.com has learned.

“We recently sent letters to players who may have had an affiliation with the company which is now claiming its products include a banned substance,” wrote NFL spokesman Brian McCarthy in an email to ThePostGame.com. “We are investigating the matter, as we have been for awhile now."

A relationship between S.W.A.T.S. owner Mitch Ross (pictured below) and several NFL players and coaches was first revealed in a Jan. 19 story on ThePostGame.com. One of the S.W.A.T.S. products, called “The Ultimate Spray,” is promoted by the company as containing deer antler velvet and IGF-1, short for Insulin-Like Growth Factor 1. IGF-1 is banned by the NFL and other major sports leagues as well as the Olympics.

“You use HGH in part to help stimulate IGF-1, which helps aid in recovery and the building of lean muscle mass,” said Travis Tygart, the CEO of the United States Anti-Doping Agency. “A lot of athletes want to go to IGF-1 directly to get the benefit.”

On Jan. 14, the league ordered Raiders coach Hue Jackson to sever ties with S.W.A.T.S., saying that coaches were not allowed to endorse supplements. Now the league wants players to disassociate themselves from S.W.A.T.S.

“Despite the company’s claims, it is not clear at all that the product actually contains IGF-1,” McCarthy wrote. “The fact that the company is claiming that its product contains a banned substance is enough to preclude players from associating with the company.”

S.W.A.T.S. is also getting the attention of a consumer watchdog group in Washington, D.C.

“We wrote to the FDA last year [about S.W.A.T.S.],” said Steve Mister, President and CEO of the Council for Responsible Nutrition. “We got a response on Nov. 8. They said they would review it. I spoke at a public conference last Thursday morning. I said if the FDA had acted quicker, they might have saved [Hue Jackson] some embarrassment. We were disappointed the FDA didn’t act quicker.”

Reached by phone Wednesday, FDA spokesperson Siobhan DeLancey said: “For these products, marketed as supplements but potentially containing anabolic steroids or analogs, we have to obtain the product and test the product. We have to prove it contains a steroid or analog before we take action.”

DeLancey said no action has been taken against S.W.A.T.S.

IGF-1 is difficult to test for, according to Jonathan Danaceau, lab director at the Sports Medicine Research and Testing Lab, which is approved by the World Anti-Doping Agency (WADA).

“Detecting it is a challenge and we’re currently working on a program to do that,” he said.

NSF International, a company that does testing for the NFL, has never been asked to test for IGF-1, according to spokesperson Kelly Nichols.

“In order to do so, we’d need to first develop a test method,” she wrote in an email to ThePostGame.com. “This takes approximately 20-30 business days and includes conducting the first test.”

Gary Wadler was chairman on the WADA committee that decided to ban IGF-1.

“This is an area that needs to be addressed,” he said. “IGF-1 poses many of the similar challenges as HGH, but it hasn’t received the attention. There is a commercial form of IGF-1, and I’m curious why that hasn’t made it into doping.”

As of Wednesday afternoon, more than a dozen NFL players are credited with online testimonials for S.W.A.T.S. products, including a holographic chip touted as increasing an athlete’s energy. Bengals defensive back Roy Williams, who told ThePostGame.com he has used the Ultimate Spray, is pictured on the S.W.A.T.S. site.

Testimonials credited to Ray Lewis and Jackson have been removed from the site, according to Ross.

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