Chao has been accused of using her office to benefit herself and her family's shipping company.
Donald Trump infamously called the city a "disgusting, rat and rodent infested mess."
The president is scheduled to speak at the House Republican Conference retreat this week despite his previous insults.
Congress is already looking into various ways the Trump administration has sought to direct business to the president's properties.
Whether the president violated the Constitution by pitching his Miami resort for the next G-7 summit is also under review.
Oversight Committee Chair Rep. Elijah Cummings said DHS is blocking staff from visiting facilities after previous inspections revealed mistreatment of migrants.
“I want him to come and look at my entire city. I’ll ride with him for hours if he asked to,” the Maryland congressman said of the president.
“This is the behavior of a jerk, a clod, a dolt, a schmuck."
Calling the president a POS was "mistaken," the EGOT winner clarified. "At least excrement has a useful biological function."
"Too bad!" Trump tweeted about the burglary of Cummings' home in Baltimore.
The congressman's home was broken into hours before Trump began tweeting racist insults about Cummings and his majority-black House district.
The House speaker says Trump's son-in-law and White House adviser knows all about the rodent infestations in Baltimore that the president has griped about.
The president continued to spread discord as he spoke in Cincinnati, Ohio.
The Housing and Urban Development secretary's team was shooed because they hadn't sought permission to host a press conference in a church lot.
"We need to get him out of office," the singer-songwriter added in a scathing interview.
Committee Chair Elijah Cummings (D-Md.) wants the names of Customs and Border Protection employees in the groups and any disciplinary records.
Shrugging off allegations of bigotry, the president said in a C-SPAN interview that "everybody’s called a racist now.”
The president has been attacking the city, its residents and Rep. Elijah Cummings (D-Md.) for days.
The former interior secretary falsely claimed last week that all probes against him were “b.s.” and that he’d been totally cleared of wrongdoing.
Faith leaders said Tuesday that the president's history of racism and his recent remarks about Baltimore are "a clarion call, and give cover, to white supremacists."