• The Department of Justice's antitrust division has informed the PGA Tour it will review the organization's proposed merger with Saudi-funded LIV Golf, NBC News reported.
• News of the DOJ's move came after Democratic Sens. Elizabeth Warren of Massachusetts and Ron Wyden of Oregon urged the federal agency to investigate the merger agreement.
• The PGA Tour's once-adversarial relationship with LIV was already under scrutiny by federal prosecutors.

The Department of Justice's antitrust division has informed the PGA Tour it will review the organization's proposed merger with Saudi-funded LIV Golf, a source told NBC News on Thursday.

The Justice Department and LIV Golf declined to comment.

In a statement to CNBC, the PGA Tour said, "We are confident that once all stakeholders learn more about how the PGA TOUR will lead this new venture, they will understand how it benefits our players, fans, and sport while protecting the American institution of golf."

A source with knowledge of the situation said that any interest by the DOJ would be an extension of the preexisting investigation, and would not be unusual for U.S. antitrust authorities to review a transaction of this profile. The source added that a review does not suggest the transaction violates antitrust laws.

The DOJ was already conducting an investigation into professional golf, in light of the litigation with LIV.

The announcement of the deal last week immediately sparked antitrust concerns.

This week, Democratic Sens. Elizabeth Warren of Massachusetts and Ron Wyden of Oregon urged the DOJ to open a probe into the agreement. Sen. Richard Blumenthal, D-Conn., also opened a probe into the deal. Wyden launched his own investigation Thursday.

The PGA Tour's once-adversarial relationship with LIV was already under scrutiny by federal prosecutors who last year started investigating whether the PGA Tour had engaged in anticompetitive behavior.

LIV, which is backed by the so-called Public Investment Fund controlled by Saudi Arabia's Crown Prince Mohammed bin Salman, divided the pro golf world when it emerged as a rival to the PGA Tour.

The upstart league's links to the kingdom, with its sordid record on human rights, triggered a swarm of controversy. But with the help of a reported $2 billion investment from the crown prince's fund, LIV dangled massive prizes and perks and managed to lure high-profile golfers to play in its tournaments.

Former President Donald Trump hosted a LIV tournament at his New Jersey golf club last summer, stoking outrage from the kingdom's critics — including families and survivors of the 9/11 terrorist attacks.

The PGA Tour and LIV Golf had locked horns in and out of court, and PGA Tour Commissioner Jay Monahan has openly criticized the rival league, making the announcement of their proposed merger all the more surprising. The announcement last week noted the tie-up would prompt a mutual end to all pending litigation.

If the merger goes through, the two entities will combine their businesses and rights into a new for-profit company. The PGA Tour policy board will have to approve the agreement, Monahan told players in a memo.

The PGA Tour revealed Tuesday that Monahan is currently recovering from an unspecified medical matter and is taking a leave of absence.