An audit that could have shed light on the inner workings of the D.C. tax office now under scrutiny was never completed even though it was required by law to be finished 19 months ago, The Washington Examiner has learned.

The D.C. Office of the Inspector General just awarded the contract for the audit last month, and it is scheduled to be finished at the end of September. The independent audit was called for two years ago, as part of the Real Property Assessments Improvement Act of 2010, which was inserted in the 2011 city budget. The act required the inspector general to contract with an outside firm to conduct an audit of the Office of Tax and Revenue "for the purposes of examining the District's management and valuation of commercial real property assessments."

The act came after city officials moved to revamp the highly criticized Board of Real Property Assessments and Appeals. According to an Examiner report at the time, the board reduced assessment on city properties by $3.3 billion in the 2009 tax year.

Now the Office of Tax and Revenue is under scrutiny following a Washington Post report calling attention to an increase in instances where the city settles assessment appeals by commercial property owners instead of defending its valuation in court. In 2012 alone, settled cases knocked roughly $2.6 billion off the total value of all properties in the city. The FBI is also reportedly looking into the issue.

A spokeswoman for Inspector General Charles Willoughby said Thursday that the office received funding for the independent audit this year but would not say what caused the delay.

The audit was to focus on several areas, including performance measures, training qualifications and hiring practices.

Willoughby was required to submit the findings by December 2010 and repeat the process every three years, "if not asked to do sooner." In addition, the act required Chief Financial Officer Natwar Gandhi to submit a five-year analysis of the assessment appeals board.

A spokeswoman for Gandhi confirmed the analysis had been completed. Gandhi and Stephen Cordi, who heads the tax office, deny allegations that the 2012 settlements cost the city millions of dollars.