JACKSON, Mississippi — The D.C. government is investigating whether Kay Webber, a longtime aide to Sen. Thad Cochran, properly registered her house for commercial uses, including renting out a basement apartment that Cochran lives in.

Webber rents the apartment to Cochran, rents the second floor of her house as a venue for campaign fundraisers and other events – including to Cochran’s campaign – and rents her house as a “bed and breakfast,” according to personal financial disclosure statements she filed with the Senate.

But a records search with the District of Columbia Department of Regulatory Affairs (DCRA) found no paperwork indicating she registered her house for those commercial purposes.

“We received a complaint alleging that there was an illegal rental at that address, and we are going to evaluate that complaint just as we do all others that come to us,” DCRA spokesman Matt Orlins said in an email to Breitbart News. “At this point, though, the sole basis for that evaluation is the complaint that we received.”

Orlins added that if there is a violation, it would be a civil–not criminal–matter, and could result in a fine of up to $2,000.

The missing paperwork was first reported by Breitbart News in a story about whether the payments to Webber by Cochran’s campaign may have run afoul of campaign finance rules. In an interview for that story, a lawyer for Cochran, William McGinley, said he had “no response” for whether Webber had filed proper paperwork with the D.C. government to rent the apartment.

“In your apartment building, is it all up to code?” McGinley’s partner, former Federal Election Commission chairman Don McGahn, also asked.

Between 2007 and 2012, according to the financial disclosures she filed with the Senate, Webber received $230,070 in income from the three sources. The bulk of that came from her renting the property to Cochran, where she reports $162,000 in income over the six-year period. Using the home a reception hall netted Webber $46,420 over that six years and she earned $28,650 using the home as a Bed and Breakfast.

Regarding the apartment, the specific approval that Webber neither received nor filed an application for is called a Certificate of Occupancy.

Cochran’s campaign did not respond to a request for comment.