WASHINGTON (AP) — The House Oversight Committee says it is investigating whether Transportation Secretary Elaine Chao acted improperly to benefit herself or her family's shipping company.

Two Democratic leaders sent a letter Monday asking Chao to turn over documents related to the New York-based company, Foremost Group. Chao's father and sisters own the company, which transports material to and from China.

The New York Times reported that Chao may have used her Cabinet position to benefit the company and increase its influence and status with the Chinese government.

Chao has denied wrongdoing.

Democratic Reps. Elijah Cummings of Maryland and Raja Krishnamoorthi of Illinois said they are examining Chao's statements and actions and whether she complied with ethics rules. Cummings chairs the Oversight panel, while Krishnamoorthi heads an economic and consumer policy subcommittee.