Lawmakers' calls to investigate the proposed merger between the US-based PGA Tour and Saudi Public Investment Fund--backed LIV Golf are escalating.

On Friday, Rep. Maxine Waters, the top Democrat on the House Financial Services Committee, and the chair of the Senate Banking, Housing, and Urban Affairs Committee, Sen. Sherrod Brown, D-Ohio, sent a letter to the US Treasury Department requesting the Committee on Foreign Investment in the United States (CFIUS) examine the national security risks of the golf tour tie-up.

In their letter to Treasury, Waters and Brown said they were "deeply concerned" by the proposed deal, writing, "Saudi Arabia has a repressive government, known for chilling dissent, jailing dissidents, and enacting draconian punishments."

The Saudi PIF, which owns LIV Golf, is chaired by Mohammed bin Salman, the Crown Prince of Saudi Arabia. US intelligence officials have accused bin Salman of carrying out the operation that murdered journalist Jamal Khashoggi in 2018. Bin Salman has denied involvement.

An investigation by CFIUS would not be the first probe into the surprise merger between the PGA Tour and LIV Golf, formerly bitter rivals.

On Thursday, the Wall Street Journal reported that the US Department of Justice would review the planned merger for antitrust concerns, citing people familiar with the matter.

The Senate Finance Committee and the Senate Permanent Subcommittee on Investigations have also opened separate probes into the deal.

Waters and Brown acknowledged the multiple investigations in their letter, writing, "We understand and appreciate that CFIUS is, by statute, an authority of last resort. As several US government agencies evaluate this announced merger and reviews its compliance with existing law and regulations, we request that CFIUS assess the nature of this merger to determine whether it has jurisdiction over the transaction and, if so, resolve any national security risks related to the transaction."

The deal between the PGA Tour, LIV Golf, and the European DP World Tour was announced earlier this month, to the surprise of many.

Before the deal announcement, PGA Tour and LIV Golf were locked in a legal battle and traded barbed accusations of unfair competition, but the two organizations agreed to drop all pending litigation under the new agreement.