New York (CNN) -- A Catholic nun pleaded guilty Thursday to embezzling $850,000 from a college in the New York City suburbs, the U.S. Southern District Attorney's Office announced in a press release.

Sister Marie E. Thornton, a 63 year-old nun, embezzled over $850,000 from Iona College starting in 1999, while functioning as its vice president of finance, the statement said.

"This is a classic case of the fox guarding the hen house," Manhattan U.S. Attorney Preet Bharara said. "Marie Thornton was entrusted with the financial well-being of Iona College, but instead, she abused her access to cook the books and line her own pockets."

According to the statement from U.S. attorney, Thornton diverted funds for personal use by submitting false vendor invoices and personal expense bills to be reimbursed by the school.

"The College took all proper actions in this situation when it was discovered almost two years ago and the majority of the missing funds were recovered," Iona said in a statement Thursday. "New procedures are in place to safeguard against a similar situation."

Iona College, a Catholic school with about 3,200 students, is located in New Rochelle, about 15 miles from Midtown Manhattan.

On Thursday, Thornton pled guilty to embezzling from an organization receiving federal funds, a charge which carries a sentence of up to ten years in prison and a maximum fine of $250,000.

Sentencing is scheduled for May 13.

Thornton's attorney could not be reached for comment.

CNN's Logan Burruss contributed to this report.