A spokesman for D.C. Chief Financial Officer Natwar Gandhi defended the city tax office's security measures one day after an employee was charged in federal court for helping to steal more than $300,000 from city taxpayers.

The Office of Tax and Revenue's safeguard and the CFO's internal auditors caught irregularities with tax refunds filed by Control Technician Kimberle Davis and referred the case to the U.S. Attorney last year, said David Umansky.

"The ongoing investigative processes led to the discovery of this matter," Umansky said.

He added that Davis lied about her outside employment at 2FT Fast Facts Tax Service, the tax preparation company for which she helped file fraudulent returns.

Davis, who was placed on administrative leave in June, was charged Tuesday. The third such employee in Gandhi's 12-year tenure to be caught stealing led Mayor Vincent Gray to say he wanted to hear more from Gandhi about how he wants to overhaul the office.

But Umansky on Wednesday said the office has no plans to make changes to the system.

"We're always reviewing the security procedures," he said, adding later, "and in this case it worked."