DES MOINES, Iowa — The former owners of a network of used-car dealerships in Iowa and South Dakota were sentenced to federal prison terms and ordered to pay millions in restitution to several banks they were convicted of defrauding.

Dan Nelson and Chris Tapken of Sioux Falls, Iowa, were sentenced to 30-month and 18-month sentences, respectively, after pleading guilty to conspiracy to cause false entries in bank books. The initial indictment, leveled in 2005, charged the pair with altering reports and making false statements to several banks, allegedly to make the dealership network appear financially stable.

Nelson and Tapken were ordered to pay $7 million in restitution to several banks, most notably Sioux Falls-based MetaBank, to which the pair were ordered to repay $3.3 million.