A Senate committee has delayed action on President Trump’s nominee to lead the Federal Aviation Administration, Stephen Dickson, so it can investigate claims by a Delta Air Lines pilot that she was subjected to retaliation after she reported safety concerns to him and other executives at the airline.

“Since holding the nomination hearing with Mr. Dickson, new information has come to the committee’s attention that merits further examination,” said Sen. Roger Wicker (R-Miss.), chairman of the Senate Commerce, Science and Transportation Committee. “The committee has been reviewing this information, and I have asked the Department of Transportation and the White House to do the same.”

Dickson, who was Delta’s senior vice president for flight operations from 2006 to 2018, could not be reached for comment Tuesday.

The allegations were contained in a lawsuit filed in June 2016 by Karlene Petitt, who said she was punished after raising concerns about pilot training and other issues at the airline. Petitt alleges that after she spoke out, Delta ordered her to undergo a psychiatric evaluation. The suit says she was diagnosed as bipolar and barred from flying for more than a year. Two other psychiatrists later examined her and determined the diagnosis was incorrect, and she was cleared to return to work at Delta, where she is a Boeing 777 pilot.

Senate aides said information about the lawsuit surfaced in the weeks following Dickson’s May 15 confirmation hearing. Dickson did meet with Senate Commerce Committee staff last week to answer questions, they said.

Dickson had not specifically mentioned the lawsuit on the questionnaire nominees are required to submit to the committee. He did note in a section titled “Legal Matters” however, that: “During my Delta employment, from time to time and in the ordinary course of business, Delta was involved in various judicial, administrative or regulatory proceedings relating to its business, although I was not a named party in any such actions.”

It’s not clear what impact the new information will have on Dickson’s nomination.

On Tuesday, the White House signaled that it was standing behind the nominee, brushing off concerns that Dickson had failed to note the lawsuit in his questionnaire.

“President Trump chose Steve Dickson to head the FAA because of his almost three decades of experience at Delta where he oversaw global flight operations,” spokesman Judd Deere said. “The White House has complete confidence in his nomination and expects him to be confirmed.”

Dickson is not named in the lawsuit, which was filed against Delta Air Lines, but Petitt’s lawyer, Lee Seham, said Dickson was among the executives to whom Petitt took her concerns.

Among her complaints, Petitt alleged that pilots were either being given the answers to exams or not taking them at all. She also complained that some instructors were falsifying training records. She was concerned pilots weren’t being properly trained to fly manually. And she was concerned about pilot fatigue, alleging that Delta was inaccurately recording “deadheading” hours or duty hours.

Seham said that in a deposition, Dickson said he supported the decision to have Petitt undergo a psychiatric evaluation, calling it a “sound course of action.”

What’s more, Seham said that Dickson and other executives failed to act on Petitt’s concerns.

“These are serious issues, and they didn’t investigate,” Seham said.

Pettit lost her motion for summary judgment in February, and the case is being appealed.

Delta executives disputed Petitt’s allegations.

“At Delta, putting safety first — always, is the driving force behind everything we do,” the airline said in a statement Tuesday. “Our utmost responsibility is to provide safe and secure travel for our customers and our employees. The very core of our safety program is employee reporting. Every single Delta employee is encouraged and empowered to report potential concerns and we do not tolerate retaliation against employees who raise concerns.”

Dickson, a former Air Force fighter pilot, was nominated by Trump to lead the FAA on March 19 — less than two weeks after the second deadly crash involving a Boeing 737 Max jet. All 157 passengers and crew members aboard the Ethio­pian Airlines flight were killed in the March 10 crash. In October, a 737 Max jet operated by Lion Air crashed shortly after takeoff killing all 189 passengers and crew aboard.

Some have criticized Trump for moving too slowly to fill the job, which has been without permanent leadership since January 2018, when Michael Huerta stepped down at the end of his five-year term.

Since then, the agency has been led on an interim basis by Daniel K. Elwell, a former American Airlines pilot who previously served as deputy administrator and in other capacities at the FAA.

Trump had wanted his personal pilot, John Dunkin, to lead the agency but was unable to garner enough support on Capitol Hill for the nomination. Ultimately, he chose Dickson for the job.

At a hearing last month, senators repeatedly pressed Dickson on whether changes needed to be made to a program that allows manufacturers to participate in the certification process for new aircraft.

While Dickson pledged a thorough examination of the FAA’s process for certifying the 737 Max, he said it was too early to commit to any specific actions, adding that if confirmed he would wait to hear from several expert panels looking into the matter before moving forward on any changes.