Kwame R. Brown might have failed to disclose more than $250,000 in campaign contributions and expenses during his 2008 bid for reelection to the D.C. Council, according to preliminary information mistakenly or inadvertently posted on the Office of Campaign Finance Web site.

Brown’s fundraising and spending during his 2008 campaign for the at-large seat has been the subject of an audit since last fall, when he ran successfully for council chairman. Elections officials became concerned about potential irregularities in his finance report.

The office launched a probe in September around the time former council member Vincent B. Orange (D) questioned the integrity of Brown’s reports. Orange, who competed against Brown (D) for chairman last year, wanted to know why his amended finance reports showed he was using his 2008 account for expenses in 2010. Those expenses were related to printing, consultants, an office alarm system and a credit card machine.

As is customary for an Office of Campaign Finance investigation, the audit of Brown’s 2008 account is being conducted out of public view. But there have been growing signs that the office is wrapping up its investigation, and officials have said a final report could be issued soon.

When The Washington Post reviewed Brown’s 2008 finance reports last week, data attached to the online file appeared to have stemmed from the audit. Brown’s list of donors included a line indicating that there had been $102,763 in “contributions previously not reported per aud[it].” There also was an entry for $169,431 in “expenditures previously not reported per audit.”

Wesley Williams, a spokesman for the Office of Campaign Finance, said the financial information was posted by mistake. It was removed from the Web site Thursday afternoon.

Williams said the figures represented “preliminary audit findings” and should be viewed as “still inconclusive.” He said an “error” in the office’s computer system resulted in the premature release of the preliminary audit findings.

Brown had until Feb. 11 to issue a written response to the preliminary findings of the audit, according to published reports. Auditors are reviewing Brown’s response so they can finish the final report, officials said.

“Once it’s finished, you get to see everything,” Williams said, adding that he cannot comment on details of what has or has not been uncovered.

Brown declined to comment on specifics of the probe but said he has been cooperating with auditors.

“We have given them all the information they need and look forward to this being brought to closure quickly,” Brown said. “I look forward to them having a quick, thorough review of the details.”

The release of the final audit could complicate Brown’s efforts to move beyond recent revelations about his personal finances and stewardship of tax dollars.

During his campaign last year, media outlets reported that three credit card companies had filed suit against him, alleging $55,000 in unpaid debts and interest. Brown told The Washington Post last summer that he estimated his personal debt at $700,000, including the mortgage on his home.

Brown also has faced criticism since news reports last month said he asked the Department of Public Works to lease him a “fully loaded” Lincoln Navigator that cost taxpayers $2,000 a month.

Brown has since returned the vehicle and pledged to refund the District for the time he used it, but it remains unclear whether the city can get out of its long-term lease. Brown told reporters March 1 that he plans to work “every day” to “win back the trust” of District residents.

When Orange raised questions about the 2008 report, Brown acknowledged some errors in reporting. In a written response to Orange’s complaint, Brown’s treasurer said the campaign had incorrectly reported a surplus in the 2008 account.