Icahn Enterprises, Carl Icahn’s conglomerate, saw its stock drop again Wednesday after a disclosure showed regulators are seeking information regarding its corporate governance.

The shares fell as much as 20% in morning trading, following a near 25% loss last week. A regulatory filing revealed the U.S. Attorney’s office for the Southern District of New York contacted Icahn Enterprises last Wednesday seeking information about corporate governance, capitalization, securities offerings, dividends, valuation, marketing materials, due diligence and other materials.

Regulators sought information a day after notable short seller Hindenburg Research took a short position against Icahn’s company. Hindenburg alleged “inflated” asset valuations last Tuesday, among other reasons, for what it says is an unusually high net asset value premium in shares of the publicly traded holding company.

“The U.S. Attorney’s office has not made any claims or allegations against us or Mr. Icahn with respect to the foregoing inquiry,” Icahn said in the 10-Q filing. “We believe that we maintain a strong compliance program and, while no assurances can be made and we are still evaluating the matter, we do not currently believe this inquiry will have a material impact on our business, financial condition, results of operations or cash flows.”

Icahn, the most well known corporate raider in history, made his name after pulling off a hostile takeover of Trans World Airlines in the 1980s, stripping the company of its assets. Most recently, the billionaire investor has engaged in activist investing in McDonald’s and biotech firm Illumina.

Headquartered in Sunny Isles Beach, Florida, Icahn Enterprises is a holding company that invests in a myriad of businesses including energy, automotive, food packaging, metals and real estate.

Last week, in response to the Hindenburg report, Icahn said in a statement that the short seller’s report was intended “solely” to generate profits on its short position at the expense of Icahn Enterprises’ long-term stakeholders.

“We stand by our public disclosures and we believe that IEP’s performance will speak for itself over the long term as it always has,” Icahn said last week. “We continue to believe that activism is the best paradigm for investing and my activist investments over the last 25 years have well proved this out.”

Shares of Icahn Enterprises are now down more than 35% year to date.