(Reuters) — Federal prosecutors have charged the owner of Archegos Capital Management Bill Hwang with racketeering and fraud as regulators said his manipulation of stock prices cost banks billions of dollars when his “house of cards” collapsed, according to documents released Wednesday.

Archegos, a family office run by former Tiger Asia manager Mr. Hwang, defaulted on margin calls in March of last year, leaving big name banks nursing heavy losses and sparking a fire sale of shares including ViacomCBS and Discovery Inc.

The blowup cost global banks including Credit Suisse, Nomura Holdings, Morgan Stanley and Deutsche Bank more than $10 billion in losses.

Prosecutors allege that Mr. Hwang, who denies wrongdoing, manipulated the stock price of seven of Archegos' portfolio companies, including Viacom, Discovery and Tencent Music Entertainment, according to an indictment brought by the U.S. Attorney's office in Manhattan.

Prosecutors say Mr. Hwang did so by deliberately misleading counterparties about the positions Archegos held and controlling the timing and size of trades to have a greater impact on price, the indictment said.

A lawyer for Mr. Hwang said in a statement the case had “absolutely no factual or legal basis.”

The U.S. Securities and Exchange Commission separately brought a complaint.

“Archegos engaged in a brazen scheme to manipulate the market,” the SEC said. “Eventually, the weight of Defendants’ fraudulent and manipulative scheme was too much for Archegos to bear, and over the course of less than a week in late March 2021, the house of cards collapsed.”

Prosecutors said that Mr. Hwang and the family office's former chief financial officer, Patrick Halligan, "corrupted the operations and activities" of the family office to manipulate the price of stocks it held and lied to banks and brokerages, which lost billions on trades.

The SEC said it had sued Mr. Hwang, Mr. Halligan, head trader William Tomita and Chief Risk Officer Scott Becker for their alleged roles in the scheme.