Washington (CNN) The Department of Housing and Urban Development's inspector general is looking into the role HUD Secretary Ben Carson's family has played at the agency, a spokesman told CNN.

Carson called earlier this month for the inspector general to "review" the role his family has played at the department after The Washington Post reported that HUD officials expressed ethics concerns about their role. Carson's son and daughter-in-law helped organize a listening tour for the agency in Baltimore last summer.

Asked Tuesday by CNN whether HUD's Inspector General has opened an investigation into the role Carson's family has played at the department, HUD IG spokesman Darryl Madden said there is "an open matter."

"We have an open matter," Madden said. "However, it is our policy not to comment any further during its pendency."

Madden declined to clarify the statement, responding to follow-up questions by saying: "We are standing by the statement."

HUD spokesman Jereon Brown referred questions on the investigation's launch to the inspector general's office. "We have nothing to add to the previous statement requesting the investigation," Brown said in an email.

Carson asked for an IG investigation after media reports about the Baltimore listening tour.

The department's lawyers warned that Carson's son's participation might risk violating federal ethics rules and the department's deputy general counsel raised those concerns directly with Carson, according to an internal memo released publicly through the Freedom of Information Act. Linda Cruciani, the deputy general counsel, left the meeting believing Carson' son and daughter-in-law would not participate in the listening tour.

"In my role as HUD secretary, I try to be as inclusive as possible and talk with a wide variety of people because when it comes to increasing access to affordable housing, no rock should remain unturned," Carson said in a statement earlier this month. "From my very first day at HUD I have insisted that HUD operate in an open and ethical manner, in every way. To clear up any suspicion I am calling for the HUD inspector general to review this matter."

Carson would be the sixth Cabinet-level member of President Donald Trump's administration to be the subject of an inspector general's investigation concerning federal ethics rules.

VA Secretary David Shulkin most recently came under fire after a report revealed that his wife improperly traveled with him on an international trip at the government's expense. Shulkin's chief of staff resigned in the wake of a damning inspector general's report on the matter, which Shulkin repudiated.

Health and Human Services Secretary Tom Price resigned in September after reports revealed he unnecessarily chartered expensive private flights.