The US Senate has launched an investigation into the planned commercial merger between the PGA Tour, DP World Tour and LIV Golf.

Richard Blumenthal, chairman of the Permanent Subcommittee on Investigation, has written to PGA Tour commissioner Jay Monahan requesting all documents and information relating to the controversial agreement.

Blumenthal has raised concerns over the involvement of the Saudi Arabian Public Investment Fund (PIF), which owns LIV Golf.

“PIF’s role as an arm of the Saudi government and PGA Tour’s sudden and drastic reversal of position concerning LIV Golf raise serious questions regarding the reasons for and terms behind the announced agreement,” Blumenthal writes.

“Prior to this agreement, PGA Tour was one of the loudest critics of LIV Golf’s affiliation with Saudi Arabia.”

Blumenthal also talks about the “risks posed by a foreign government entity assuming control over a cherished American institution” and notes that the PIF is using its investment in sport to “further the Saudi government’s strategic objectives”.

The PGA’s intention to preserve its tax-exempt status once the merger has been completed raises additional concerns, according to the Democratic Party senator for Connecticut.

The documents requested by the investigation must be provided by June 26, three weeks after news of the merger broke.

While signalling the end of a year of unprecedented disruption in the men’s professional game following the launch of the LIV Golf circuit, the arrangement is highly contentious and has been met with shock by some players.