By Chris Isidore and Ahiza Garcia

PHILADELPHIA (CNN) — Golfer Phil Mickelson was charged with profiting from insider trading by the Securities and Exchange Commission on Thursday, but he faces only civil, not criminal, charges.

Two other individuals allegedly involved in the insider trading case with Mickelson are Las Vegas investor and gambler Billy Walters and Thomas Davis, the former chairman of Dean Foods. Walters and Davis were named in federal criminal indictments unsealed Thursday.

The charge against Mickelson involves a July 2012 conversation he had with Walters. According to the SEC, Mickelson and Walters were friends, and the golfer owed the gambler for bets.

Walters had insider information from Davis about an upcoming spin-off Dean Food was planning, and Walters advised Mickelson to buy its stock, according to the complaint.

Mickelson allegedly bought $2.4 million worth of the stock the next day, dwarfing his total stock holdings of $250,000. When the stock rose in price, Mickelson was able to sell it at a $931,000 profit and pay off his bets with the proceeds of the trade, according to the SEC. The agency is seeking to collect at least the $931,000 profit from Mickelson.

Federal courts have recently reigned in prosecutors in insider trading cases. The government must now prove that anyone who got a tip knew that they were receiving nonpublic information. U.S. Attorney Preet Bharara, who brought the cases against against Walters and Davis, recently had to drop a number of insider trading cases because of this more stringent requirement.

But the SEC only brings civil cases, which require a lesser burden of proof than criminal cases.

Gregory Craig, a former White House counsel who represented Mickelson in the past, did not immediately respond to a request for comment Thursday. Nor did his agent.

Mickelson, 45 is one of the most successful and popular golfers. He has lifetime earnings of $79.5 million, second only to Tiger Woods’ total. And his winnings have been dwarfed by his endorsement money. He earned $48 million in 2015, according to an estimate from Forbes. His sponsors include KPMG, Rolex, Barclays, Amgen, Exxon Mobil and Callaway.

The U.S. attorney’s office in Manhattan has scheduled a press conference at noon ET.

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