Marrying an married woman

You are witness of the marriage of both the parties and their identities.  Neither more nor less.  You are not attesting any fact about their marital status at the time of their marriage.   If any illegality is found about their marital status in future, you will not be held accountable.  So do not worry.  If you file a representation withdrawing your signature, it will complicate the matter to that couple.

Dear Querist

you can read the answer of your query in experts

Trouble not only for couple but for your as well.  Whom will you convince that the abetment to fradulent marrige was done by you without knowledge of earlier marriage.

At the time of registration did the woman mention that she's divorced or unmarried?

If that is so, then how can the witness be held for abetting fraud marriage?

prosecution has to only prove that witness knew about the earlier marriage (i he really knew) and abetment will be proved.  if he never knew and can prove it then there can be no proof against him and he will (if accused) discharged after proonged suffering of trail.