The D.C. chief financial officer’s integrity office opened more than 50 investigations last year into employees accused of theft, embezzlement, bribery and other misconduct, as the effort intensifies to weed out workers who may be ripping off taxpayers.

The disclosure comes as prosecutors are continuing their investigation into the theft of millions of dollars from the D.C. treasury by a pair of Office of Tax and Revenue employees. Harriette Walters and Diane Gustus are accused of manipulating the tax-refund process for two decades under the nose of CFO Natwar Gandhi.

"I used to brag about our reputation," Gandhi told a D.C. Council committee Wednesday. "We are now considered incompetent, inefficient, cheats. We need to regain the trust of the people."

The CFO’s Office of Integrity and Oversight in fiscal 2007 investigated 52 employees accused of threats, thefts, embezzlement, bribery, assault, illegal drugs and falsification of documents, according to its annual report. Of those cases, 42 were closed, all but nine with disciplinary action: One employee was fired, four left voluntarily, four were reprimanded and three were suspended.

The report further revealed that six employees were fired for lying about their pasts, including one whose background check exposed an undeclared embezzlement conviction and a felony charge for theft. Roughly 600 CFO employees who started before 1999 will have their backgrounds checked in the next year at a cost of $108,000.

Ward 2 Councilman Jack Evans, chairman of the finance and revenue committee, said the oversight report "raises concerns in light of the tax scandal." But he expressed confidence that Gandhi and Robert Andary, the new integrity director, would "ferret out employees who are not of an honest nature."

Andary’s predecessor, Ben Lorigo, was castigated for missing signs of the tax theft. Andary’s office now has three auditors working full time to assess risks within the CFO’s automated tax systems, while new OTR Director Stephen Cordi is working on the "significant undertaking" of improving internal control, he told the panel.

Fifteen OTR employees have been removed since the tax office scandal broke in November. There are more personnel actions to come, Gandhi said, but not until he gets the green light from the U.S. attorney.

At a glance

Chief financial officer oversight findings from fiscal 2007

» Tax office delivered a letter containing taxpayers’ unmasked Social Security number to the wrong address.

» CFO released Social Security numbers of 1,900 police officers while responding to a Freedom of Information Act request.

» Employee fired after background investigation revealed an active warrant for his arrest.