D.C. Council member Michael A. Brown said Friday that he fears “a substantial” amount of money may have been embezzled from his reelection account, and he is working with investigators to determine how much is apparently missing.

Speaking a day after he said he replaced his treasurer because of “unauthorized disbursements,” Brown (I-At Large) said the allegedly missing funds have put a noticeable dent in his campaign account.

“Those dollars are gone,” Brown said.

Brown said he discovered the discrepancy last Friday while conducting a standard review of his campaign finance reports. After suspecting the money was missing, Brown said he personally replaced his campaign treasurer, Hakim J. Sutton, and called D.C. police.

Brown stressed Friday that he does not know who is responsible for the alleged theft.

Michael Brown, shown in 2009, fears “a substantial” amount of money may have been embezzled from his campaign account. (BILL O'LEARY/THE WASHINGTON POST)

D.C. Police Chief Cathy L. Lanier confirmed Friday that officers executed a search warrant in the case Thursday, but she added that she was not prepared to discuss the matter.

“I can’t comment on evidence,” Lanier said. “It’s an ongoing investigation.”

Sutton, a veteran Democratic operative and fundraiser, did not return a call seeking comment Friday.

Brown said he is working with police, fraud investigators and the D.C. Office of Campaign Finance to figure out how the alleged embezzlement happened. Officials with the OCF said they are aware of the situation.

Some officials with knowledge of the matter but who are not allowed to speak publicly about it have said the missing funds could exceed $50,000, but Brown on Friday cautioned that the figure was premature.

“I just don’t know yet, but it’s very troubling,” Brown said.

Brown, who is up for reelection in November, said he and police are investigating when the alleged fraud began.

“In my general oversight of the records, I noticed stuff just didn’t look right, seem right, and upon further discovery, I found something wrong and called [police] immediately,” Brown said.

Brown, who is also the council’s chairman pro tempore, said he also sent an e-mail to Sutton to inform him that he was being dismissed. “I’m very disappointed; it’s someone who has been around and part of my campaigns for quite some time,” Brown said. “I’m sorry these things happen.”

Brown’s campaign problem comes as Mayor Vincent C. Gray (D) and several council members have struggled with questions about their campaign finances.

Former council chairman Kwame R. Brownpleaded guilty to a misdemeanor count this month following a federal probe of his 2008 campaign. Two former Gray campaign aides have pleaded guilty in a separate, ongoing probe of the mayor’s 2010 effort. Gray has denied any wrongdoing.

In March, D.C. Council member Vincent B. Orange (D-At Large) acknowledged that he accepted more than $20,000 in “suspicious” donations from Jeffrey E. Thompson, a city contractor whose home and office were raided as part of the federal investigation into campaign practices.

According to the most recent report filed with the OCF, Michael Brown’s campaign has taken in nearly $148,000 and has spent about $32,000. The campaign reported having $115,515 on hand as of the June 10 reporting period.

But Brown said he would probably be making revisions to his campaign report to reflect the missing funds. Brown said he also expects to sue to try to recoup some of the money.

L. Asher Corson, Brown’s campaign spokesman, said “it’s possible some or all of the money could be recovered during the course of the investigation.”

If that does not happen, it remains unclear how the loss would affect Brown’s reelection chances against six candidates vying for two at-large seats in November.

Brown noted he won’t be able to go back to supporters who have already donated maximum contributions to his campaign. Still, Brown remained optimistic Friday, saying “our yard signs are popping up and people are calling asking where they can send checks.”

“The campaign is moving forward,” he said.