A government watchdog group formally requested Monday that the Office of Congressional Ethics mount an investigation to discover if Rep. Mario Diaz-Balart, R-Fla., committed bank fraud in connection with a pair of mortgages the congressman took out.

The organization, the American Democracy Legal Fund, detailed in its complaint that Diaz-Balart could have also received an improper gift in violation of House ethics rules.

The ADLF complaint, first reported Tuesday by the blog Florida Politics, cited a pair of mortgages Diaz-Balart took out, one on a home in Miami and another on a condominium in Washington.

For both mortgage applications, Diaz-Balart indicated the property could be his “primary address,” which typically receive lower interest rates than second homes.

Also, it is impossible to have two primary addresses, as they are defined as where the homeowners live most of the time. Homeowners in both Florida and the District of Columbia receive tax deductions on their primary residences.

Yet Diaz-Balart “still qualified for and executed mortgages that would otherwise be unavailable to the general public under the same conditions,” according to the ADLF complaint, written by its president, Brad Woodhouse.

The existence of the two mortgages was first reported by DCReport, a nonprofit news service run by the journalist David Cay Johnston, who made headlines last year for publishing parts of President Donald Trump’s 2005 tax return.

The story prompted an investigation by the Miami-Dade County property appraiser, who concluded on Oct. 12 that Diaz-Balart’s Florida residence was indeed his primary residence, based on a search of driver’s license and vehicle registration records.

The property appraiser’s report also said Diaz-Balart did not receive a homestead exemption on his property in Washington.

That still raises the question whether the eight-term congressman was able to secure the lowest rates possible, which ADLF argued could qualify as mortgage fraud as well as a violation of the House’s gift rule.

“Rep. Diaz-Balart received loans and tax exemptions he likely did not qualify for, and under more generous terms than he otherwise would have received, by simultaneously presenting as his primary residences the Miami home and D.C. condo,” Woodhouse wrote.

Woodhouse called for an immediate ethics investigation.

“Rep. Diaz-Balart’s conduct strongly indicates that he has failed to conduct himself in a manner that will reflect creditably on the House of Representatives,” he wrote.

Florida Politics reported that the Diaz-Balart’s aids were confident he did nothing wrong: “The facts speak for themselves.”