U.S. securities regulators are probing Taser International Inc.'s (TASR) claims about the safety of its stun guns and a recent order from a distributor, the company said.

Taser shares, among the market's hottest stocks during the past two years, fell as much as 23 percent following the news, which Taser released in a statement shortly before midnight on Thursday.

The Scottsdale, Ariz., company said it was compiling information after receiving the informal inquiry letter from the Securities and Exchange Commission (search).

According to Taser, regulators are focused on its statements about the safety of its stun guns (search). The electric-shock devices recently were the target of a critical report by Amnesty International (search), which alleged that more than 70 people had died in the United States and Canada over the past four years in Taser-related incidents.

"We are confident our statements are supported by the safety studies of our products," Rick Smith, Taser chief executive officer, said in a statement. "We are in the process of compiling the information requested by the SEC."

The SEC is also inquiring about a recent order received by Taser from Davidson's Inc (search) , which distributes its products.

In December, Taser said it had agreed to a deal for Davidson's to market and distribute its Taser X26C Citizen Defense (search) stun gun to firearms dealers.

Taser said the SEC letter states: "This inquiry is non-public and should not be construed as an indication by the commission or its staff that any violation of law has occurred, nor should it be considered a reflection upon any person, entity or security."

Since the beginning of 2003, Taser shares have risen more than 8,000 percent.