Responsa for Bava Kamma 229:25
נרשאה גנב ספרא זבניה לפפונאה בתמנן זוזי אזל פפונאה זבניה לבר מחוזאה במאה ועשרין זוזי לסוף הוכר הגנב אמר אביי ליזיל מרי דספרא ויהב ליה לבר מחוזא תמנן זוזי ושקיל ספריה ואזיל בר מחוזאה ושקיל ארבעין מפפונאה
from a certain person. The latter stole a garment and brought it to him [as a pledge] and borrowed on it four further <i>zuz</i>. As the thief was subsequently identified, the case came before Rabina<span class="x" onmousemove="('comment',' 'Rabbanai' according to Hyman, Toledoth, 88; for similar deviations, cf. supra 113b with B.M. 2a. ');"><sup>43</sup></span> who said: Regarding the former [four <i>zuz</i>] it is a case of a thief misappropriating articles and paying a debt [with them] in which case the plaintiff has to pay nothing whatsoever,<span class="x" onmousemove="('comment',' As decided supra, this page. ');"><sup>44</sup></span>
Teshuvot Maharam
A. A owes that amount to B. Since the court has a right to distrain a debtor's article for the benefit of the creditor, the court may surely confirm B in the possession of the book after the latter pays to A the difference between its actual value and the price he had originally paid. If B paid C for the book more than the latter paid to the Gentile, C must return the difference to A.
SOURCES: Am II. 138.