A former commissioner will plead guilty to lying to grand jurors investigating bond deals that have Alabama's largest county on the brink of the largest municipal bankruptcy in U.S. history, a prosecutor said Tuesday.

Mary Buckelew, 62, admitted to a single count of obstruction for denying that an investment banker showered her with about $4,000 worth of high-priced shoes, a purse and spa treatments during three trips to New York to discuss bond sales and swap transactions in 2003 and 2004.

U.S. Attorney Alice Martin said Buckelew, who served on the commission from 1990 through 2006, admitted knowing the gifts were meant to influence her decisions on financing massive improvements to the county's sewer system.

"As a result of these corrupt transactions, Jefferson County is now in a financial crisis of unprecedented proportions," Martin said during a news conference.

Additional charges are likely, she said.

Martin did not identify the investment banker who provided gifts to Buckelew from Salvatore Ferragamo, a chic Fifth Avenue boutique, and an unidentified spa where the commissioner ran up a tab of $1,400.

The total value of the gifts wasn't huge, but Martin said they were still part of a web of corruption.

"I would think most people in Alabama have not spent $1,400 on a spa in one day. I haven't," she said.

Buckelew admitted to lying to grand jurors during an appearance on Aug. 11, documents show. She faces penalties ranging from supervised release to 20 years imprisonment plus a fine of $250,000.

An attorney for Buckelew did not immediately return a telephone call seeking comment.

Unable to pay off $3.2 billion in debt because of ballooning interest payments, Jefferson County is trying to negotiate a way out of filing what would be the largest bankruptcy ever by a local government.

Acting at the suggestion of outside advisers, the county borrowed money for a huge sewer project on the bond market in a complex and risky series of transactions. When the mortgage crisis hit and banks began tightening up on lending, interest payments on the debt skyrocketed.

Buckelew's plea deal comes amid a federal corruption scandal involving contracts awarded on the sewer project. Twenty-one people have been convicted, including contractors, engineers and two other former county commissioners who served with Buckelew.