The pro golfer reportedly transferred nearly $3 million to an intermediary as a part of "an illegal gambling operation which accepted and placed bets on sporting events," an investigation by ESPN's Outside the Lines revealed.
Citing two unnamed sources and court documents, ESPN reported Mickelson sent a wire transfer in March 2010 of $2.75 million to Gregory Silveira of La Quinta. Silveira pleaded guilty to three counts of money laundering, ESPN reported.
Mickelson has not be charged with a crime and is not under investigation, according to ESPN.
Last year, Mickelson was cleared of any wrongdoing in an insider trading case involving Clorox stock, although he might still be a person of interest in another investigation regarding Dean Foods stock, according to Bleacher Report.