General Electric shares fell more than 13 percent on Thursday morning after Madoff whistleblower Harry Markopolos targeted the conglomerate in a new report, accusing it of issuing fraudulent financial statements to hide the extent of its problems.

A website has been set up to disseminate the report, www.GEfraud.com, where Markopolos calls it “a bigger fraud than Enron.” The financial investigator, who was probing GE for an unidentified hedge fund, writes that after more than a year of research he has discovered “an Enronesque business approach that has left GE on the verge of insolvency.”

“My team has spent the past 7 months analyzing GE’s accounting and we believe the $38 billion in fraud we’ve come across is merely the tip of the iceberg,” Markopolos said in the 175-page report. Markopolos alleges that GE has a “long history” of accounting fraud, dating to as early as 1995, when it was run by Jack Welch.

One area of Markopolos’ case focuses on GE’s long-term care insurance unit, for which the company had to boost reserves by $15 billion last year. By examining the filings of GE’s counterparties in this business, he alleges that GE is hiding massive losses that will only increase as policyholders grow older. He claims that GE has filed false statements to regulators on the unit. Separately, he goes on to find issues with GE’s accounting on its oil and gas unit Baker Hughes.

“The allegations we have heard are entirely false and misleading,” GE said in a statement. “The Company has never met, spoken to or had contact with Mr. Markopolos, and we are extremely disappointed that an individual with no direct knowledge of GE would choose to make such serious and unsubstantiated claims. GE operates at the highest level of integrity and stands behind its financial reporting. We remain focused on running our businesses every day, following the strategic path we have laid out.”

“GE will always take any allegation of financial misconduct seriously. But this is market manipulation — pure and simple,” Lawrence Culp, chairman and CEO of GE said in a statement. “Mr. Markopolos’s report contains false statements of fact and these claims could have been corrected if he had checked them with GE before publishing the report.”

The Wall Street Journal first reported on Markopolos’ findings, sending GE shares lower.

Markopolos is a Boston-based accounting expert who gained attention after pointing out irregularities with Madoff’s investment strategy, and how it was impossible to generate the returns the fraudster claimed years before the Ponzi scheme was exposed. He was largely ignored at the time. More recently, Markopolos helped uncover a foreign currency trading scandal at a group of banks.

“GE has been running a decades long accounting fraud by only providing top line revenue and bottom line profits for its business units and getting away with leaving out cost of goods sold, SG&A, R&D and corporate overhead allocations,” the report said.

GE’s market value as of Wednesday’s close was $78.8 billion. With Thursday morning’s skid, the market cap was down to $68.5 billion. Markopolos told the paper the insurance unit would need to raise reserves by more than $18.5 billion.

GE is already under investigation by the Justice Department and SEC for potential accounting practices. That includes a $22 billion charge the company took in the third quarter related to acquisitions made in its power business.

The struggling industrial conglomerate abruptly removed its former chief executive officer and chairman John Flannery last year after only a year on the job and installed former Danaher CEO Lawrence Culp as his successor.

Flannery had been appointed in August 2017, taking the reins from Jeff Immelt as GE’s stock steadily eroded. The company’s value continually set new lows as investors remain unconvinced by Flannery’s turnaround vision. Last summer, GE was kicked out of the Dow Jones Industrial Average. It had been the longest-serving component of the blue chip index at 111 years.

Long-term care policies typically pay for end-of-life costs, like nursing homes or assisted living. It’s known as one of the more costly and unpredictable parts of the insurance market — especially as the average American lifespan rises. In January 2018, GE reported a $6.2 billion charge based on liabilities in its long-term care business, which is run by the company’s financial services unit, GE Capital. To make up for the costs, GE Capital said it needed to set aside $15 billion to hold against potential losses, and stopped paying a dividend to its parent company for the “foreseeable future.”

The costs prompted an investor lawsuit and prompted an investigation by the Securities and Exchange Commission, with whom GE has said it is cooperating.