General Electric shares fell as much as 15% on Thursday after fraud investigator Harry Markopolos, who blew the whistle on Bernard Madoff's Ponzi scheme, said GE was concealing deep financial problems.

In a 175-page report, Markopolos accused GE of hiding $38.1 billion in potential losses and asserted that the company's cash situation was far worse than it had disclosed.

"GE's true debt to equity ratio is 17:1, not 3:1, which will undermine its credit status," Markopolos said.

The report says GE is insolvent and asserts that its industrial businesses have a working capital deficit of $20 billion.

The report echoes the assertions of some of Wall Street's more skeptical analysts, who have long raised alarms about GE's low cash flow, frequent accounting charges and writedowns and what they describe as opaque financial reports.

The report adds that "GE's $38 billion in accounting fraud amounts to over 40% of GE's market capitalization, making it far more serious than either the Enron or WorldCom accounting frauds."

In a statement GE said: "We remain focused on running our business every day and ... will not be distracted by this type of meritless, misguided and self-serving speculation."

GE said it "stands behind its financials" and operates to the "highest-level of integrity" in its financial reporting.

GE said Markopolos was known to work for unnamed hedge funds that typically benefit from short selling a company's stock.

A disclaimer in the report stated that it was drafted by Forensic Decisions PR LLC, which will get compensation from a third-party entity that could benefit from a decline in GE's share price. The report did not name the entity.

Speaking on CNBC on Thursday, Markopolos said he would receive a percentage of any profits generated by the report, but declined to provide details about the compensation or name the fund involved, which he said was "a midsized U.S. hedge fund."

GE shares were down 11% at $8 in morning trading.

In the past two years GE has announced more than $40 billion in asset writedowns and accounting charges. The company also has said its accounting is being investigated by the U.S. Securities and Exchange Commission and the Department of Justice.

The report details GE's exposure to long-term care insurance, the subject of a federal class-action lawsuit awaiting a decision on GE's motion to dismiss.

It says GE's financial statements about its insurance business do not correspond to those of eight insurers that Markopolos says hold about 95 percent of GE's exposure.

Markopolos is best known for alerting regulators in the early 2000s to signs that money manager Bernard Madoff's investment firm was a Ponzi scheme, a deception in which unusually high returns for early investors are generated with money from later investors. Madoff was arrested in 2008 and later sentenced to 150 years in prison for the fraud.

John Hempton co-founder of the Sydney, Australia-based Bronte Capital hedge fund, wrote in a blog post Thursday that GE's 14.7% average profit margin in recent years was in line with the returns of its industrial peers, not "too good to be true" as Markopolos alleges.

"GE remains the unequivocal leader" in medical imaging and jet engines and its currently depressed profit margin will likely rebound, he wrote, adding, "Harry's report is silly. The market should ignore it."