US Justice Department officials are investigating the US PGA Tour over possible anti-competitive behavior regarding the Saudi-backed LIV Golf Series, the Wall Street Journal reported on Monday.
The report comes three days before the start of the year's final major tournament, the British Open at St. Andrews, where LIV Golf players will be allowed to compete for the Claret Jug.
The Justice Department refused to comment on the report but Golf Channel and Golf Digest reported the PGA Tour had confirmed the investigation.
American stars Phil Mickelson, Dustin Johnson, Patrick Reed, Bryson DeChambeau and Brooks Koepka are among those who have defected to upstart LIV Golf, which offers the richest purses in golf history at $25 million and 54-hole events instead of the usual 72.
The US PGA Tour responded by banning players indefinitely who competed in LIV Golf's first two events, 17 players last month in England and seven more earlier this month in the United States.
Player agents have received inquiries from Justice Department anti-trust investigators regarding US PGA Tour bylaws governing player participation in other golf events and about the PGA's recent actions regarding LIV Golf, the Journal reported.
"This was not unexpected," a US PGA Tour spokesman said. "We went through this in 1994 and we are confident of a similar outcome."
US PGA Tour anti-trust moves were investigated in 1994 when Australian star Greg Norman tried to start a rival tour, but the probe ended in 1995 with no action taken against the PGA Tour.
Norman is now commissioner of LIV Golf, which has drawn controversy and protests due to human rights issues with the circuit's Saudi financiers.
The 1990s investigation looked at the PGA's ban on members playing in competing events, which requires a release by the tour.
While those have been granted to events on other tours at times, no releases were given for the LIV Golf tournaments, which conflicted with US PGA Tour events.
Some players who jumped to LIV Golf have dropped PGA membership but others, including six-time major winner Mickelson, have kept their PGA spot.
Norman has called the PGA Tour a "monopoly" and sees the players as independent contractors, so a legal fight could be coming over the bans and release system, the tour saying it has the right to discipline members who violate its rules.
The next LIV Golf event is scheduled for July 29-31 at Trump National Golf Club in Bedminster, New Jersey.
Those are also the final three days of the US PGA Tour's Rocket Mortgage Classic in Detroit.
LIV Golf players were allowed to compete at St. Andrews by the R&A as they were last month at the US Open by the US Golf Association.
But US 2023 Ryder Cup captain Zach Johnson has hinted that only PGA members in good standing would be allowed on his team next year.