D.C. Council member Michael A. Brown (I-At Large) reported late Monday that more than $100,000 went missing from his campaign treasury this summer, essentially wiping out most of the money he had available to spend on his bid for reelection.

In an amended campaign finance report, which the Board of Elections required Brown to file by midnight, the first-term council member adjusted his campaign reports to account for $113, 950 in “unexplained expenditures.” The loss leaves Brown with only about $18,000 in the bank

In July, Brown made a surprise announcement that he was firing his campaign treasurer after discovering what he called a “substantial” amount of money missing from his campaign account. Brown called D.C. police, who launched an investigation.

No charges have been filed in the case, but a police investigation is continuing.

For much of the summer, Brown declined to disclose the exact dollar figure he feared was missing. But after Brown’s opponents in the Nov. 6 election demanded that the city’s elections board require Brown to more accurately account for his losses, the board ordered the council member to file an amended report.

In a letter to elections officials, Brown said the revised report, which covers the period from March 11 to June 10, lists 34 new “unexplained expenditures,” totaling $113,950. Some of the unexplained expenditures date back to July 2011.

But Brown has said little publicly about the missing money. He is expected to hold a news conference on Tuesday afternoon.

In a statement, Brown apologized to his supporters but attributed the loss to a “crime.”

“To my supporters and contributors, I am deeply sorry that this happened and that it occurred under my leadership,” Brown said. “Since personally taking control of the campaign finances as treasurer, I have righted the ship.”