A disgraced former Internal Revenue Service manager and his estranged wife were sent to prison Monday for their part in the largest taxpayer rip-off in District history.

Robert Steven was sentenced to 46 months in prison and his wife, Patricia, was given 70 months in prison for helping their friend, self-confessed tax scam mastermind Harriette Walters, pilfer more than $48 million through a series of phony property tax refunds.