Five people convicted of operating an estimated $100 million tax refund fraud operation that stands as one of the nation’s largest are facing prison sentences in South Florida federal court.

The ring was centered in an unassuming house in the suburb of Miramar. Internal Revenue Service investigators say at least 10 laptop computers were used between July 2011 and May 2013 to steal tens of millions of dollars in fraudulent refunds using stolen identities.

Federal prosecutors say it’s one of the largest such fraud cases ever uncovered.

The Miramar group, all men in their 20s and early 30s, pleaded guilty earlier this year to fraud, identity theft and stolen mail possession charges. They are scheduled for sentencing Tuesday by a Fort Lauderdale federal judge.

(AP)