The Defense Department Office of Inspector General said Wednesday that it had opened an investigation into whether acting Secretary Patrick Shanahan had used his position to improperly promote his former employer, Boeing.
The investigation comes after the nonprofit Citizens for Responsibility and Ethics in Washington (CREW) filed a complaint with the watchdog's office last week, alleging that Shanahan appeared to make statements promoting Boeing and disparaging competitors, such as Lockheed Martin.
Pentagon spokesman Tom Crosson said in a statement that Shanahan welcomes the review.
"Acting Secretary Shanahan has at all times remained committed to upholding his ethics agreement filed with the DoD," said Crosson. "This agreement ensures any matters pertaining to Boeing are handled by appropriate officials within the Pentagon to eliminate any perceived or actual conflict of interest issue(s) with Boeing."
Shanahan, 56, joined Boeing in 1986 and spent more than 30 years there before Trump nominated him as deputy secretary of defense in March 2017. Shanahan became acting defense secretary at the beginning of this year following the resignation of James Mattis.
Shanahan signed an ethics agreement in June 2017 that outlined the steps he would take to avoid "any actual or apparent conflict of interest," and said he would not participate in any matter involving Boeing.
The complaint, based to a large part on published reports, including one by Politico in January, said Shanahan has made comments praising Boeing in meetings about government contracts, raising concerns about "whether Shanahan, intentionally or not, is putting his finger on the scale when it comes to Pentagon priorities."
One example raised by the complaint is the Pentagon's decision to request funding for Boeing 15EX fighter jets in the 2020 proposed budget. The Pentagon is requesting about $1 billion to buy eight of the aircraft.
While at Boeing, Shanahan led the company's missile defense and military helicopter programs and is credited with rescuing the troubled Dreamliner 787 program. Trump has seemed attracted to Shanahan partially for his work on one of the president's pet projects — creating a Space Force.
He has also lauded Shanahan's former employer, Boeing, builder of many of the military's most prominent aircraft, including the Apache and Chinook helicopters, the C-17 cargo plane and the B-52 bomber, as well as the iconic presidential aircraft, Air Force One.
The probe comes as Boeing struggles to deal with a public firestorm over troubles with its Boeing 737 Max 8 jetliner. And it focuses attention on whether Trump will nominate Shanahan as his formal pick for defense chief, rather than letting him languish as an acting leader of a major federal agency.
This is only the third time in history that the Pentagon has been led by an acting chief, and Shanahan has served in that capacity for 85 days, longer than any of the others. Bill Clements served as acting defense secretary for 39 days in 1973, while William Howard Taft IV spent 66 days in the job in 1989.
The Associated Press contributed to this report.