Phil Mickelson has been named in an insider trading lawsuit. Picture: AP

The five-time major-champion golfer was named in a federal insider-trading lawsuit overnight, claiming that he made nearly $US1 million ($1.4 million) from non-public information in the trading of Dean Foods stock, The New York Post reports.

Golfer Phil Mickelson and high-profile sports better Billy Walters. Picture: SuppliedSource:Supplied

The complaint was filed by the Securities and Exchange Commission in the US District Court for the Southern District of New York. Because the case is in civil court, the SEC is seeking “all ill-gotten gains in the form of illicit trading profits.”

Also named in the suit is Billy Walters, who is a well-known sports gambler and allegedly passed on the information to Mickelson in July of 2012.

Mickelson allegedly made almost $US1 million after getting the insider trading tip from Walters and then used some of the money to pay back Walters, to whom he allegedly owed money.

US golfer Phil Mickelson poses for pictures with his wife Amy (top L) and children Evan Samuel, Amanda Brynn and Sophia Isabel after winning the 2013 British Open Golf Championship. Picture: AFPSource:AFP

Phil Mickelson holds the Claret Jug after winning the 2013 British Open Golf Championship. Picture: AFPSource:AFP

Thomas C. Davis, who is the former head of Dean Foods, is also listed as a defendant.

Mickelson, 45, has played 12 events on the PGA Tour this season, with his best finish being a tie for second at the AT&T Pebble Beach Pro-Am in February.

He most recently missed the cut at the Players Championship at TPC Sawgrass last week.

In his career, Mickelson has made $US79,530,749 of prize money, along with many endorsements.

This article originally appeared in The New York Post