"I understand this concern on behalf of the taxpayers.
People want value for money. That's why we always
insist on the principal of Information Retrieval
charges. It's absolutely right and fair that those
found guilty should pay for their periods of detention
and the Information Retrieval procedures used in their
interrogations."
The check Lowry delivers to Mrs. Buttle is a check for the amount debited from the Buttle's charge account when Mr. Buttle was interrogated and killed (because of Information Retrieval's torturous methods) early in the film. The police officer says to Sam after he is strapped into the chair at the torture chamber "Don't fight it son, confess quickly. If you hold out too long, you could jeopardize your credit rating." Note that this is not merely a funny line; a scene present only in the ER (and presumably in the laserdisc) has a MOI official arranging a way for Sam to pay his charges via installments.
Inspiration for this subplot may have possibly stemmed from German history -- the Nazis were known to charge Jews for their forced passage to the concentration camps.