The FDA is warning New York-based Driven Sports to fix its Craze sports supplement because they claim it contains a methamphetamine-like compound in its proprietary blend of ingredients.

The letter, which is available to the public on the FDA website, was dated April 4. Driven Sports stopped making Craze months ago, but has already found a replacement for it called Frenzy. Frenzy is not available for sale in the U.S.

The FDA wrote the letter to Matt Cahill, a felon who has continued to put risky diet supplements on the market over the years.

This is the first action taken against Craze after safety concerns about the pre-workout energy supplement have persisted for over a year. In 2012, the supplement which promises "endless energy," was named "New Supplement of the Year" by bodybuilding.com.

In the letter to Cahill, the FDA questions the ingredients listed on Craze's packaging. It questions whether compounds that Craze claims to come from dendrobium orchids really come from the plant. Craze calls this proprietary blend of ingredients "Dendrobex." The FDA says Craze never submitted paperwork to have this blend of ingredients approved.

In an independent study by a research team that included a Harvard scientist last October, the team found a methamphetamine-like compound, N,alpha-diethylphenylethylamine. The FDA is not aware of this compound being found in the food supply and thus without the proper paperwork, the ingredient is not "all-natural" like Driven Sports claims.

Also in the letter to Driven Sports, the FDA warns the company that continued sales of products containing "Dendrobex" could result in seizure of products and injunctions against manufacturers and distributors.

Driven Sports has responded, insisting that Craze does not contain a meth-like compound. It says that scientists are mistaken in their findings.

Just last week, an Olympic bobsledder was disqualified for his use of Craze in the Sochi Olympics. His team finished 27th in the Winter Olympics.

Retailers like Wal-Mart started pulling Craze off the shelves after a USA TODAY investigation in July and Driven Sports ceased production of the product in October in response to all of the negative media.

Cahill and Driven Sports are not new to negative findings in its products. In 2008, he put a supplement on the market that contained an anti-estrogen drug. For this, he is facing a pending felony for "introduction and delivery of unapproved new drugs into interstate commerce with the intent to defraud and mislead."

Then in 2005, Cahill and a partner introduced another supplement into the market. This weight-loss pill contained a highly toxic mixture of pestcide and baking powder. For this unapproved drug, he served 24 months in prison for conspiracy to commit mail fraud and introduction of a misbranded drug into interstate commerce.

Before he headed to prison though, he concocted another mixture, this time the steroid Superdrol. Superdrol was later linked to liver damage.

With his checkered past, Cahill doesn't seem to shy away from creating risky new supplements. With Frenzy already said to be the replacement for Craze, users are praising the energy they are getting from Frenzy. But, it's too early to tell if Frenzy contains dangerous, controversial ingredients like Cahill's past creations.