After Andre J. Hornsby quit as chief executive of the Prince George's County school system May 27, the senior staff he had assembled during two years in office remained stable for several weeks. But last month, one of Hornsby's top lieutenants, Chief Financial Officer Wynette Wilkins, was forced out.

An Aug. 12 letter from interim schools chief Howard A. Burnett, obtained last week by The Post, indicated that Wilkins was placed on administrative leave Aug. 15 and that her employment would end Oct. 11. The letter described the termination as a "discharge" and gave no elaboration.

Wilkins, who lives in Upper Marlboro, joined the system in January 2004 after serving as a top finance officer for the D.C. police. As CFO for the Prince George's schools, she earned about $150,000 a year. She declined last week to comment on her departure.

Asked about a recent internal audit that showed payroll errors resulting in more than $1 million of wage overpayments to school system employees during the past two fiscal years -- money that school officials are attempting to recover -- Wilkins referred The Post to her previous written responses to that audit. In one passage, Wilkins wrote that she had recommended seeking an outside consultant to help stabilize the payroll system.

"However, the CEO in conjunction with the [school] board chose not to move forward with the . . . recommendation," Wilkins wrote.

The internal audit did not appear to say which senior officials were responsible for the errors. Along with the finance staff led by Wilkins, human resources and information services staff members were involved in payroll and related computer database issues. Until he was named interim chief, Burnett led the human resources department.

The school system's financial operations have come under heavy scrutiny in the past year as outside auditors encountered delays in their efforts to review financial statements. However, independent auditors from BDO Seidman LLP recently certified the school system's books for fiscal 2004 as accurate.