Related for Yevamot 74:23

והוינן בה לרבנן שפיר קאמר אדמון ואמר רב יהודה אמר רב הכא במאי עסקינן כגון שהקיפוה ארבעה בני אדם מארבע רוחות

Said R. Abba in the name of Rab: The judgment must stand.<span class="x" onmousemove="('comment',' Once the levir received a half of the estate of his deceased brother it cannot again be taken away from his heirs. The second claim of the 'doubtful son' is, therefore, invalid. ');">³⁹</span> R. Jeremiah said: The judgment is to be reversed.<span class="x" onmousemove="('comment',' The sons of the levir must either return to the 'doubtful son' the half which their father had received or allow him in their father's estate a share equal to theirs. ');">⁴⁰</span>

Shulchan Arukh, Even HaEzer