Federal prosecutors are preparing to announce criminal charges as early as this week against SAC Capital, just days after the U.S. unveiled a civil case against the hedge fund's founder, billionaire Steven Cohen. 

FOX Business’s Charlie Gasparino confirmed the timing of the criminal charges, which was earlier reported by The Wall Street Journal.

A criminal case could mark the demise of the very successful, $15 billion hedge fund as no major financial firm has survived a criminal indictment.

A spokesperson representing SAC declined to comment.

U.S. authorities have been scrutinizing the activities of Stamford, Conn.-based SAC and its founder for years, searching for evidence to support allegations of insider trading.

Last week, the Securities and Exchange Commission charged Cohen with failing to supervise portfolio managers and prevent insider trading, but stopped short of hitting him with actual insider trading charges. The administrative charges filed by the SEC could lead to a monetary penalty and Cohen being barred from the industry. .

A criminal indictment could be derailed by a last-second settlement, however SAC said in May its cooperation with the government investigation was "no longer unconditional."

In response to the SEC’s civil case, SAC said the administrative proceeding “has no merit” and Cohen “acted appropriately at all times and will fight this charge.”

The SEC alleged Cohen “ignored red flags” tied to suspicious 2008 trading in shares of two drug makers and Dell (DELL) and failed to supervise two senior employees and prevent them from engaging in insider trading. The senior employees, Mathew Martoma and Michael Steinberg, have each been hit with insider-trading charges over the past two years.

SAC is the most visible target of a four-year effort to curtail alleged insider trading on Wall Street that has resulted in charges against 81 individuals.

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