From: Rabbi Moshe Sofer
To: Unknown recipient
A childless man who claimed throughout his life to have a brother died without giving a get, potentially binding his wife to yibum; investigation showed his claimed family connections in Fürth were fabricated. The Chasam Sofer exhaustively examines multiple grounds for leniency — chezkas heter, single-witness testimony, the husband's own hearsay report of the brother's death, and the husband's demonstrated intent to give a get — but finds serious halachic difficulties with each avenue and ultimately cannot permit the wife to remarry, deferring to a greater authority.
Source: Shu"t Chasam Sofer EH II §72