The House Oversight Committee has opened a probe into allegations that Transportation Secretary Elaine Chao has used her office to benefit herself and her family.

In a letter to Chao on Monday, Chairman Elijah Cummings (D-MD) and Rep. Raja Krishnamoorthi (D-IL) argued that several media reports in recent months had indicated the transportation secretary — who also happens to be married to Senate Majority Leader Mitch McConnell (R-KY) — had used her official position to promote her family shipping company within the Chinese government.

The congressmen also pointed to a trip that Chao was supposed to take to China that was canceled in October 2017. It was widely reported that Chao attempted to include her family members in official meetings with Chinese government officials. The committee is also interested in probing why Chao decided not to divest from her stock in Vulcan Materials Company, a construction company that “depends heavily on infrastructure funding allocated by DOT,” the letter said.

“The Committee is examining your misstatements of fact, your actions that may have benefitted the company in which you continued to hold shares, and your compliance with ethics and financial disclosure requirements,” the two lawmakers wrote, asking for documents relevant to the press reports by the end of the month.

Read the letter below: