Updated

A former comptroller accused of stealing $53 million from her small northern Illinois city to fund a lavish lifestyle, including one of the nation's foremost horse-breeding operations, is expected to plead guilty on Wednesday, federal prosecutors said.

Rita Crundwell is expected to plead guilty to federal charges accusing her of stealing the public money while overseeing the public finances of the city of Dixon, U.S. attorney's spokesman Randall Samborn said. Prosecutors said she stole the money over several years and siphoned it into a secret bank account.

Crundwell had previously pleaded not guilty to one federal count of wire fraud, which carried a maximum sentence of up to 20 years in prison.

Crunwell's federal public defenders, Paul Gaziano and Kristin Carpenter, did not immediately return messages seeking messages Tuesday afternoon. Crundwell, who is free on a recognizance bond, is scheduled to appear before U.S. District Judge Philip G. Reinhard in Rockford federal court on Wednesday.

Prosecutors allege that since 1990, the 58-year-old Crundwell stole more than $53 million from Dixon, where she oversaw public finances as the city comptroller since the 1980s. The small city is about 100 miles west of Chicago.

Authorities say Crundwell bought luxury homes and vehicles, and spent millions on her horse-breeding operation, RC Quarter Horses LLC, which produced 52 world champions in exhibitions run by the American Quarter Horse Association.

Prosecutors say Crundwell's scheme unraveled only after a co-worker filling in for her while she was on an extended vacation stumbled upon the secret bank account.

Her arrest stunned Dixon, a small city along a picturesque vein of the Mississippi River in Illinois farm country. Its 16,000 residents are largely lower-middle class, working at factories, grain farms, the local prison and a hospital, among other places.

Crundwell also has pleaded not guilty to 60 separate but related felony theft counts in Lee County.