A company that planned to sell home anthrax-testing kits saw its stock price plunge by 55 percent after promising to stop marketing the tests while federal authorities investigate.

"We are suspending any efforts to market the product," Vital Living Products said in a statement Friday. Calls to the company's offices and company president Donald Podrebarac's home on Saturday were not immediately returned.

Vital Living Products confirmed Friday that it is under investigation by the Securities and Exchange Commission. The FBI raided its offices and a related New Jersey lab on Thursday.

The company's stock closed at 20 cents Friday.

Vital Living caught national attention soon after the first mail-borne cases of anthrax were detected by announcing it would sell the first over-the-counter anthrax test kit by Thanksgiving.

Vital Living said two large national retail chains would carry the PurTest anthrax kits. By early November, the company said it had received more than $150,000 worth of orders.

The company's stock, which had been trading at 5 cents on Oct. 1, rose to a high of $2.03 on Oct. 23.

But public health experts raised questions about the reliability of a home test kit and said inaccurate results could create panic. Those concerns led retailers to say they wouldn't stock the kits in their distribution centers, although individual stores could still order them.

Podrebarac said he planned to have an independent lab validate the kits before they went on the market.

Vital Living announced Tuesday that a New Jersey lab, Sani-Pure Food Laboratories, had confirmed the reliability of the test kits. Vital Living backed off that statement Friday, saying that Sani-Pure's report included inaccurate information. The SEC has subpoenaed the report.