CHICAGO (CBS) — A 73-year-old bookkeeper from Northbrook faces up to five years in prison, after pleading guilty to a years-long corporate tax fraud scheme that cheated the federal government out of more than $24 million in taxes.

Federal prosecutors said Barry Poticha, a bookkeeper for two unnamed Chicago area staffing companies, has pleaded guilty to one count of conspiracy to defraud the United States.

According to the plea agreement, Poticha admitted scheming with an independent contractor to falsify corporate tax returns and W-2 forms for more than 10 years, starting in 2000. Federal prosecutors said, when employees discovered discrepancies in their W-2 forms, Poticha issued letters to cover up the fraud.

Poticha admitted the scheme cost the federal government a total loss of more than $24 million in tax revenue.

He also admitted to falsifying his personal income tax returns from 2010 through 2015, underreporting his personal income. According to the plea deal, his personal tax fraud cost the federal government more than $340,000 in taxes, and cost the state of Illinois more than $32,000 in taxes.

The conspiracy conviction carries a sentence of up to 5 years in prison.

Poticha’s sentencing has been scheduled for August 14, before U.S. District Judge Gary Feinerman.