The Internal Revenue Service says it’s investigating a large-scale tax refund scheme run from a Minnesota prison. The case apparently involves hundreds of phony tax returns from 2006 to 2012 that contain fraudulent and fictitious information, including wage and withholding details. The IRS is reportedly focusing on an inmate in the Stillwater state prison who is due to be released in May, although refunds from the bogus returns were split among co-conspirators. Authorities are also investigating some alleged accomplices outside of prison. The IRS hasn’t said how much money was involved in the alleged scheme.