Mehmet Oz -- a.k.a. Dr. Oz -- testifies before the Senate Commerce Committee in June.
(Reuters)

Researchers have retracted a bogus study that was used by a company to validate weight-loss claims for green coffee bean pills, one of several questionable supplements being scrutinized by federal regulators.

The study, which was conducted in India but written by researchers from the University of Scranton in Pennsylvania, initially claimed that people who used the supplement lost 16 percent of their body fat (about about 18 pounds each) with or without diet and exercise.

Now, the paper has been taken down from an open-access scientific journal's Web site with this message: "The sponsors of the study cannot assure the validity of the data so we, Joe Vinson and Bryan Burnham, are retracting the paper."

Applied Food Science, the company that marketed the pills, recently settled with the Federal Trade Commission for $3.5 million after regulators looked into the questionable weight-loss claims associated with the product. The FTC raised questions about whether the study that the company's findings were based on had been based on falsified information -- including the weight of participants and the length of the study.

The use of green coffee extract is one of several questionable weight-loss schemes that have been endorsed by syndicated television personality Mehmet Oz, also known as Dr. Oz.

We've written in the past that Dr. Oz called the product a "magic" weight-loss product and touted the now-debunked research on his show.

"You may think magic is make believe, but this little bean has scientists saying they found a magic weight loss cure for every body type," Oz exclaimed in the Green Coffee Extract episode of his show. "This miracle pill can burn fat fast for anyone who wants to lose weight. This is very exciting and it's breaking news."

Oz touted the "staggering newly released study" that showed participants lost an "astounding" amount of fat and weight -- 17.7 pounds and 16 percent of body fat -- by doing absolutely nothing except taking the supplement.

As of this posting, Oz's Web site has been entirely scrubbed of almost every mention of the green coffee extract, including the episode touting the product and the "independent" experiment he and his show conducted to present their own evidence of the substance's weight-loss effects. The 2012 episode has also vanished from YouTube due to a "copyright claim by doctoroz."

In light of the study's retraction, Dr. Oz has posted a new message on his Web site (although it can be found only if you search for it):

In prior seasons, we covered Green Coffee Extract and its potential as a useful tool for weight loss. Recently the authors of the peer reviewed research paper on which our coverage had been partially based formally retracted their study. While this sometimes happens in scientific research, it indicates that further study is needed regarding any potential benefits of Green Coffee Extract.

In summary: We were wrong about green coffee extract, but that's science!

The controversy over Oz's seemingly wild claims about weight-loss products have landed him in front of Congress and caused some problems for people who associate themselves with him.

Based on Oz's new statement, it's not clear whether his show is taking a different tack and more responsibly informing his audience about weight loss-strategies that are actually scientifically proven to work.

We've reached out to Oz's office for further comment, and we will update if we hear back.