From: Rabbi Moshe Sofer
To: Unknown recipient
The Chasam Sofer rules that where a kol and eidei ki'ur arose while the woman was still married, her subsequent divorce creates a transition from one chazakah of prohibition to another (mi'issur l'issur), and she remains prohibited to the boel. He advises separating them through indirect communal pressure if necessary, questions the validity of the kiddushin performed with relative-witnesses, and rules the first husband exempt from paying the stipulated one hundred gold coins since the woman's own marriage to the suspected man strengthened the original suspicion.
Source: Shu"t Chasam Sofer EH I §26