According to an ESPN Outside the Lines report, an ex-sports gambling handicapper, Gregory Silveira, was a conduit for an offshore gambling scheme and pleaded guilty last week to laundering roughly $2.75 million of money, belonging to an unnamed "gambling client," who was Mickelson. 

It currently remains unclear exactly how Mickelson and Silveira are connected, but ESPN legal analyst Lester Munson explains that Mickelson hasn't faced any legal scrutiny because federal gambling laws are aimed at gambling organizations and not at individual bettors. The five-time major winner, who has piled up more than $77 million in earnings in over 30 years on the PGA Tour, declined to comment through his attorney.

Documents obtained by Outside the Lines show that money from Mickelson's account was transferred to Silveira's Wells Fargo Bank accounts in transactions of $2.475 million and $275,000. The next day, Silveira transferred the $2.475 million to another one of his accounts, this one at JPMorgan Chase Bank. The transactions are part of the money laundering charges.