Liberty Media, the commercial rights holder of Formula 1, has been notified by the Department of Justice in the United States that it is being investigated by its Antitrust Division.

The investigation, which Liberty Media has stated it is fully cooperating with, surrounds the rejection of Andretti Global’s failed attempt to join the F1 grid.

“This morning, we announced that there is a DOJ investigation,” confirmed Greg Maffei, Liberty Media’s CEO, in an investor call.

“We intend to fully cooperate with that investigation, including any related requests for information.

“Our determination, F1 determination, was in compliance with all applicable US antitrust laws, and we’ve detailed the rationale for our decision vis a vis Andretti in prior statements.

“We are certainly not against the idea that any expansion is wrong,” he added.

“There is a methodology for expansion that requires approval of the FIA and the F1.

“We’re certainly open to new entrants making applications and potentially being approved if those requirements are met.”

Andretti was one of four applicants when the FIA opened an Expressions of Interest process for new teams last year.

It was the only to clear the first hurdle, with its application then assessed by Formula 1 itself.

In January, it was announced that the effort had been rejected with a detailed statement was issued outlining the reasoning.

That included the claim Andretti Global offered no additional value to Formula 1.

Further, it argued the reliance on obligation to supply power unit regulations had the potential to damage the sport’s prestige.

Andretti had initially secured a supply with Renault, though as that agreement had lapsed, it had instead intended to use an FIA-mandated supply until General Motors arrived in 2028 with its own power unit.

The decision not to allow the team onto the grid caught the eye of law makers in the United States when Mario Andretti was called to Capitol Hill.

Mario Andretti, 1978 world champion and father of team owner Michael, subsequently claimed he’d been intimidated by Maffei at an event during the Miami Grand Prix.

“I was asked to go there,” Andretti told NBC.

“And just as I was trying to explain that to Stefano, Greg Maffei, Mr. Maffei, broke in the conversation and he said: ‘Mario, I want to tell you that I will do everything in my power to see that Michael never enters Formula 1′.

“I could not believe that,” he added.

“That one really floored me. … We’re talking about business. I didn’t know it was something so personal.

“That was really — oh, my goodness. I could not believe it. It was just like a bullet through my heart.”

On May 1, a dozen Members of Congress wrote to Maffei requesting information on the decision and process.

That was followed by a letter to Maffei and F1 CEO Stefano Domenicali from Jim Jordan, chairman of the Committee Judiciary asking for further information.

In the wake of that, a letter from seven US Senators wrote to the Assistant Attorney General raising concerns at the rejection and calling for an investigation.

“…we have serious concerns that the rejection of Team Andretti-Cadillac was based on a desire to exclude a rival from the racetrack, marketing opportunities, and prestige that competing in F1 can lend to a car manufacturer competing to sell cars across the globe,” that letter stated.

“While the FOM claims that it did not consult with current teams before rejecting Team Andretti-Cadillac, it notably references consultations with “key stakeholders,” which likely include team sponsors, including car manufacturers that directly compete against General Motors and Cadillac.

“That F1 stakeholders may have engaged in concerted action to exclude Team-Andretti-Cadillac – especially after it met all technical requirements to join F1 – that merits investigation.”

Despite the rejection, Andretti has continued working towards an F1 berth, acquiring a new facility to house the project at Silverstone.

That included securing the services of Pat Symonds, formerly F1’s internal technical director who joined from the commercial rights holder in May.