The commissioner of the PGA Tour and the head of Saudi Arabia's Public Investment Fund have six-days to respond to a summons from the US Senate.
The Permanent Subcommittee on Investigations wants to talk to Jay Monahan, Yasir Al-Rumayyan and LIV commissioner Greg Norman.
The Committee is looking into the proposed agreement between golf's main bodies.
Leona Maguire goes into the year's second major a player in form, following last week's victory at the LPGA Classic.
The Cavan golfer tees of her first round at the Women's PGA Championship in New Jersey just before 1.30, Irish time.
Stephanie Meadow will be out just under an hour before Maguire.
Tom McKibbin and John Murphy are among the field for the BMW International Open, which gets underway this morning in Munich.
On the PGA Tour, Shane Lowry tees off just after 1pm Irish time at the Travelers Championship in Connecticut.
Rory McIlroy and Seamus Power go out either side of 6.
